Caterpillar 10
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar Ten is a crawler (track-type) tractor built by Caterpillar Tractor Co. in Peoria, Illinois from 1928 to 1933 - the smallest tractor Caterpillar ever built. It runs a Caterpillar-built 4-cylinder L-head (side-valve) gasoline engine of 2.3 L (143 cu in) displacement, 85.7 mm x 101.6 mm (3-3/8 in x 4 in) bore and stroke, rated 1,500 rpm, with Eisemann G4 magneto ignition and an Ensign Bet-1 carburetor. Operating weight runs 2,004-2,041 kg (4,420-4,500 lb) depending on gauge and configuration. Caterpillar built roughly 4,929-4,932 standard units on a single PT serial prefix, plus about 397 High Crop high-clearance units. The Ten replaced the earlier Caterpillar 2-Ton in the lineup and was itself succeeded around 1932-33 by the 'Little' Fifteen, a mechanically related, more powerful machine on a similar chassis. Caterpillar offered the Ten as a standard narrow-gauge machine (940 mm / 37 in track centers), a wide-gauge machine (1,118 mm / 44 in track centers), and the low-volume High Crop variant with a modified final drive for extra ground clearance.
Across its production run the Ten stayed mechanically consistent - same engine, same 3-speed gear transmission and single dry-plate clutch, same mechanical clutch-and-brake steering - with the visible change being Caterpillar's December 1931 switch from gray to Hi-Way Yellow paint, a line every pre-1932 and post-1931 Ten falls on either side of. Serial-number production data show the heaviest output in 1929-1930, with much smaller batches in the opening and closing years. There is no factory dealer parts network for the Ten today; it survives as a pre-war collector antique, valued for representing Caterpillar's first purpose-built small gas crawler after the 1925 Best-Holt merger and for establishing the narrow-gauge/wide-gauge/high-clearance configuration pattern Caterpillar carried into later small-crawler lines. Low total production and 90-plus years of age make it genuinely scarce; parts support today comes from machinists reproducing wear items, magneto rebuilders, and the antique-tractor restoration community rather than any current parts catalog.
Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.
Caterpillar 10 specifications
Overview
| Model / series | Caterpillar Ten (also catalogued as Caterpillar 10). Single production series, no lettered sub-model (not related to the later D10 dozer line). |
| Production years | Production ran roughly 1928 to 1932, with a small tail into 1933. Serial run PT1 through about PT4932. |
| Units built | Approximately 4,929 to 4,932 total. About 4,535 in standard narrow-gauge form and roughly 397 in the high-clearance wide-gauge form. |
| Factory | Peoria (East Peoria), Illinois, USA. |
| Original list price | About $1,100 at introduction. |
| Configuration note | Offered as standard narrow-gauge chassis and a high-clearance wide-gauge chassis (modified final drive with reversed crown wheel and an extra reduction gear). No bulldozer-blade version was catalogued; the machine was sold as an agricultural/utility drawbar and belt-pulley crawler. |
Engine
| Engine make/type | Caterpillar 4-cylinder, water-cooled, vertical L-head (side-valve) gasoline engine. |
| Displacement | 143.1 cu in (2.3 L). |
| Bore x stroke | 3-3/8 x 4 in (86 x 102 mm). |
| Rated engine speed | 1,500 rpm. |
| Ignition | Magneto ignition (Eisemann model G4, per the original test report). |
| Carburetor | Single updraft carburetor (Ensign type, per the original test report). |
| Air cleaner | Oil-bath (oiled) air cleaner. |
| Lubrication | Combination pressure and splash lubrication. |
| Emissions | Not applicable. Predates any emissions-certification requirement. |
Weights
| Operating weight | Reported as 2,004 to 2,041 kg (4,420 to 4,500 lb) depending on configuration and equipment fitted. Treat as a single-configuration figure; no separate published weight split between narrow- and wide-gauge chassis. |
Dimensions
| Overall length | Reported 238 to 254 cm (93-3/4 to 100 in). Varies by configuration and whether a drawbar/hitch is included in the measurement. |
| Overall width | 134 cm (52-3/4 to 53 in). |
| Overall height | 131 cm (51-1/2 to 51-3/4 in). |
| Wheelbase | 217 cm (85-5/8 in). |
| Ground clearance | 23 cm (9-1/4 in). |
| Track gauge (standard) | 94 cm (37 in) between track centers, narrow-gauge chassis. |
| Track gauge (wide/high-clearance) | 112 cm (44 in) between track centers, high-clearance chassis. |
| Track shoe / chain | About 20 cm (8 in) shoe face width; roughly 4.2 m (13.9 ft) of track chain in contact length per side. |
| Belt pulley | 24 cm (9-1/2 in) diameter x 17 cm (6-1/2 in) face, running at 1,050 rpm for a rim speed of about 793 m/min (2,600 ft/min). |
Performance
| Travel speed, forward | Three forward speeds: low 3.25 km/h (2.02 mph), intermediate 4.17 km/h (2.59 mph), high 5.63 km/h (3.50 mph). |
| Travel speed, reverse | One reverse speed: 3.33 km/h (2.07 mph). |
| Drawbar power | Catalog (claimed) rating 7.5 kW (10 hp). Independent test result about 11.1 to 11.4 kW (14.9 to 15.3 hp) — figures vary slightly by test method. |
| Belt / PTO power | Catalog (claimed) rating 10.4 kW (14 hp). Independent test result about 13.5 kW (18.1 hp). |
| Maximum drawbar pull | Reported at about 2,075 kg (4,575 lb) in low gear. This figure appears in only one spec compilation and is not cross-confirmed elsewhere — treat as indicative. |
| Steering / braking | Multiple-disc clutch steering with contracting-band brakes acting on the final drives. No separate gradeability figure is published for this model. |
| Ground pressure | Not published for this model. Factory ground-pressure figures were not a standard catalog item for crawler tractors of this era. |
Blades
| Blade options | No integral dozer blade was catalogued for this model. It was marketed as an agricultural/utility crawler using a rear drawbar hitch and belt pulley for implements. A 2.1 m (7 ft) sickle-bar mower attachment was offered, shared with the Fifteen and Twenty-Two models of the same period. If evaluating a non-factory blade conversion, verify configuration with a vintage-equipment specialist. |
Service Capacities
| Fuel tank | 64.3 L (17 US gal). |
| Cooling system | 15.1 L (16 US qt). |
| Engine oil (crankcase) | Not documented in available literature for this model — consult the original operator's manual or a period service manual. |
| Transmission / final drive lubricant | Not documented in available literature for this model — consult the original operator's manual or a period service manual. |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
10 fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with filter) | Not documented in surviving public specification data for this model. | No factory-branded oil line existed for this era of machine (predates Cat DEO and similar branded oils by decades). Period practice for this gasoline L-head engine was a straight, non-detergent SAE 30 mineral motor oil in warm weather, dropping to a lighter grade (SAE 20 or 20W) for cold starts. Verify against surviving instruction-book literature if an exact fill quantity is needed. |
| Cooling system | Approx. 15.1 L (16 US qt), per period tractor-test data. | Plain water was standard for this era; no Cat-branded coolant (ELC or similar) existed yet. In freezing climates, owners of the period added alcohol- or calcium-chloride-based antifreeze; low-silicate glycol coolant is the common modern substitute used by restorers. |
| Fuel tank | Most commonly cited as 64.3 L (17 US gal); one period specification instead lists 83 L (22 US gal). Treat as varies by configuration and confirm against the tank on the specific unit. | Gasoline (the Ten used a 4-cylinder gasoline engine, not diesel — do not substitute diesel fuel specs from later Cat crawler tractors). |
| Transmission (3-speed spur-gear, dry-disc clutch — no powershift fitted) | Not documented in surviving public specification data. | No factory fill spec located. Restorers commonly run a straight SAE 140 hypoid gear oil, API GL-4 or lower (low-phosphorus/sulfur formulations are preferred so as not to attack the bronze bushings used in this transmission). Owners note the original factory-fill lubricant on unrestored units is typically found as an extremely heavy, almost tar-like gear oil; modern 90-weight gear oils are considered too thin and prone to leaking past the original seals. |
| Steering clutches / final drives (each side) | Not documented in surviving public specification data; final drive and steering-clutch compartments are commonly reported as sharing the same heavy gear-oil fill as the transmission. | Same lubricant as the transmission — straight SAE 140 hypoid gear oil, API GL-4 or lower, low-phosphorus formulation preferred for the non-ferrous bushings. No bevel-gear power-steering unit is fitted; steering is by mechanical clutch-and-brake, not a hydraulic or bevel-gear steering compartment as used on later, larger Cat track-type tractors. |
| Hydraulic system / tank | Not applicable — no hydraulic system is standard equipment on this model. | Not applicable. This tractor predates hydraulic implement control; blade or drawbar attachments of the period, where fitted, were cable- or lever-operated, not hydraulic. Do not apply Cat HYDO-type specs from later crawler tractors to this model. |
| Pivot shaft / track-frame equalizer | Not a factory-specified fluid fill; serviced as a grease point. | General-purpose chassis grease at the equalizer/pivot-shaft grease fitting, per standard practice for crawler track-frame pivots of this era. No exact factory grease interval or type located. |
| Grease points (track rollers, idlers, chassis, steering clutch linkage) | Not applicable (grease, not a fluid fill volume). | No exact factory grease specification located for this model. Owners and restorers commonly use a standard multipurpose NLGI No. 2 chassis grease for track rollers, idlers, and linkage pins; original-era grease on unrestored machines is often a very heavy, dark cup grease applied via a hand grease gun. |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar 10 maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 50 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 5,000 h |
|
Servicing the 10 beyond the schedule
Predictive Maintenance & Fluid Analysis
The Ten predates oil sampling and hour-meter diagnostics, so 'predictive' maintenance means trained senses. Check crankcase oil for a milky look or fuel smell, both signs of a leaking head gasket or worn rings. Listen for magneto misfire or spark irregularity at idle - an early warning of worn Eisemann G4 points or a failing condenser. Watch exhaust color: black smoke points to a flooding Ensign carburetor, blue smoke to worn valve guides or rings. Track sag and pin movement, checked weekly, flags undercarriage wear before it reaches the sprockets.
Corrective & Common Repairs
Typical Ten failures center on ignition and wear parts. Eisemann G4 magneto points and condensers wear first and cause hard starting or misfire; test and dress them before chasing other faults. The dry-plate clutch slips or chatters once linings soak up leaked engine oil or wear thin - reline it and fix the leak together. Steering clutch and band brakes wear unevenly and pull the tractor toward one track; adjust or reline the affected side. Worn track pins and bushings show as slack the idler screw can't remove.
Overhaul & Rebuild Points
Major rebuild work on the Ten centers on the L-head engine and undercarriage. A top-end job means pulling the head, decarbonizing the chamber, reseating valves and resetting tappet clearance. A bottom-end rebuild covers rebore and piston/ring replacement, crankshaft regrind, and main and rod bearing renewal. Rebuild the Eisemann magneto with new points, condenser, and bearings rather than replacing it outright - factory-new units no longer exist. Undercarriage rebuilds mean turning or replacing track shoes, pins, bushings, idlers, and sprockets together, since mixed wear states throw the chain out of pitch.
Seasonal & Environment Servicing
The Ten's open station and gasoline L-head engine need weather-specific care. Before storage, drain the radiator or use period-correct alcohol antifreeze - the cooling system has no factory ethylene-glycol protection. Keep the Eisemann magneto and ignition wiring dry; moisture in the breaker box is the top cause of no-start complaints after winter lay-up. Orchard and grove work, the Ten's classic role, packs the undercarriage with mud and debris - clean rollers and idlers each session to slow pin wear. High Crop units in row crops need extra final-drive gear-oil checks.
10 attachments & work tools
Blades
The 10 (Ten) left the factory as a bare drawbar/belt-pulley tractor built 1928-1932/33; no blade type (S, SU, A) or VPAT option is cataloged for it, since those designations and hydraulic angling systems postdate this model by decades. Small independent shops fitted cable-lifted "bull-grader" style blades to crawlers of this class from about 1929 onward, but adding a blade to the Ten meant heavy retrofitting rather than a factory option, so any dozer-blade Ten seen today is an aftermarket or later conversion, not an original configuration.
Rippers
No ripper attachment (single-shank, multi-shank, or parallelogram) is documented for the 10. Ripper attachments only entered the Caterpillar track-type tractor line in later decades on much larger models, so single- vs multi-shank comparisons do not apply to this 1928-1932/33 class.
Winches
No factory-cataloged winch or cable-control unit is documented for the 10. Its only power take-off was a stationary belt pulley (about 24 cm / 9.5 in diameter, 16.5 cm / 6.5 in face width, roughly 1,050 rpm) used to run separate belt-driven farm or shop equipment, not a rear drawworks or towing winch.
Drawbars/counterweights
The tractor was built primarily for drawbar work, rated at roughly 7.5 kW (10 hp) claimed drawbar output (about 11 kW / 14.9 hp on test) for pulling plows, discs, and orchard implements off a rear drawbar/hitch. No separate counterweight attachment is documented; the machine's own operating weight of about 2,005-2,041 kg (4,420-4,500 lb, figures vary by configuration) served as its working ballast.
Cab/ROPS guarding
The 10 was built with an open operator's seat and platform; no cab, canopy, or rollover protective structure was offered, since ROPS standards did not exist until long after production ended in the early 1930s. Forestry- or waste-handling guard packages, which are a modern dozer feature, do not apply to this model.
Hydraulic arrangement notes
The 10 predates hydraulic implement control entirely. Any blade or tool actuation of that era on machines this size used mechanical cable and hand-lever linkages rather than hydraulics, and no front or rear hydraulic circuit is documented for this tractor.
All 10 assemblies by section
Every catalogued assembly group for the Caterpillar 10. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Caterpillar 10 Ripper
8p4436 Hydraulic Pin Puller Arrangement
| 8J***71 | Cylinder Group; Hydraulic Cylinder Group | 1 |
| 8P***36 | Hydraulic Pin Puller Arrangement | 1 |
| 8P***37 | Pin Puller Lines And Valve Group | 1 |
8p4437 Pin Puller Lines And Valve Group
| 8P***37 | Pin Puller Lines And Valve Group | 1 |
9j4536 Ripper Arrangement--Single Shank
| 3G***60 | Ripper Group; Ripper Group | 1 |
| 4B***58 | Screw (Identification Plate) Mounting | 2 |
| 5P***27 | Plate, Serial Number; On Right Hand Ripper Mounting Bracket | 1 |
9j62 Ripper Arrangement--Multishank
| 3G***55 | Ripper Group; Ripper Group | 1 |
| 4B***58 | Screw (Identification Plate) Mounting | 2 |
| 5P***27 | Plate, Serial Number; On Right Hand Ripper Mounting Bracket | 1 |
8j2071 Hydraulic Cylinder Group (Change 0-5)--4" (101.6 Mm) Bore X 5.50" (139.7 Mm) Stroke
| 8J***71 | Cylinder Group; Hydraulic Cylinder Group | 1 |
1u3373 Hydraulic Cylinder Group (Change 0)--101.6 Mm (4 In.) Bore X 138.9 Mm (5.5 In.) Stroke
| 1U***73 | Cylinder Group | 1 |
3g2222 Lift Cylinder Group--L.H. (Change 5, 6)--266.7 Mm (10.5") Bore X 613 Mm (24.13") Stroke--Type 2 Part Of 9j1905 And 9j4537 Ripper Arrangements Listed On Pages 4, 5 & 6
| 3G***22 | Cylinder Group-Ripper Lift | 1 |
3g2221 Lift Cylinder Group--R.H. (Change 0-4)--266.7 Mm (10.5") Bore X 613 Mm (24.13") Stroke--Type 1 Part Of 9j1905 And 9j4537 Ripper Arrangements Listed On Pages 4, 5 & 6
| 3G***21 | Cylinder Group-Ripper Lift | 1 |
3g2222 Lift Cylinder Group--L.H. (Change 0-4)--266.7 Mm (10.5") Bore X 613 Mm (24.13") Stroke--Type 1 Part Of 9j1905 And 9j4537 Ripper Arrangements Listed On Pages 4, 5 & 6
| 3G***22 | Cylinder Group-Ripper Lift | 1 |
3g2221 Lift Cylinder Group--R.H. (Change 5, 6)--266.7 Mm (10.5") Bore X 613 Mm (24.13") Stroke--Type 2 Part Of 9j1905 And 9j4537 Ripper Arrangements Listed On Pages 4, 5 & 6
| 3G***21 | Cylinder Group-Ripper Lift | 1 |
3g2220 Tilt Cylinder Group--(Change 3)--2 Required--209.5mm (8.25 In.) Bore X 818.6 Mm (32.23 In.) Stroke-Type 2
| 3G***20 | Cylinder Group-Ripper Tilt | 1 |
3g2220 Tilt Cylinder Group (Change 0-2)--2 Required--8.25" (209.5 Mm) Bore X 32.23" (818.6 Mm) Stroke-Type 1 Part Of 9j1905 And 9j4537 Ripper Arrangements Listed On Pages 4 And 5
| 3G***20 | Cylinder Group-Ripper Tilt | 1 |
9j4538 Ripper Frame Group
| 9J***38 | Frame Group-Ripper; Ripper Frame Group | 1 |
9j1908 Ripper Frame Group
| 9J***08 | Frame Group-Ripper; Ripper Frame Group | 1 |
1u901 Attachment Lines Group--Type 1
| 1U***01 | Lines Group-Attachment; Attachment Lines Group | 1 |
1u901 Attachment Lines Group--Type 2
| 1U***01 | Lines Group-Attachment; Attachment Lines Group | 1 |
1u901 Attachment Lines Group--Type 3
| 1U***01 | Lines Group-Attachment; Attachment Lines Group | 1 |
3g7055 Ripper Lines Group--Type 2
| 3G***55 | Lines Group-Ripper; Ripper Lines Group | 1 |
3g7052 Ripper Lines Group
| 3G***52 | Lines Group-Ripper; Ripper Lines Group | 1 |
3g7055 Ripper Lines Group--Type 1
| 3G***55 | Lines Group-Ripper; Ripper Lines Group | 1 |
9j1906 Ripper Mounting Group
| 9J***06 | Mounting Group-Ripper; Mounting Group | 1 |
9j4542 Pin Puller Group--Type 2
| 9J***42 | Puller Group-Pin; Puller Pin Group | 1 |
9j4542 Pin Puller Group--Type 1
| 9J***42 | Puller Group-Pin; Puller Pin Group | 1 |
9j1905 Ripper Arrangement--Multishank
| 3G***20 | Cylinder Group-Ripper Tilt | 2 |
| 3G***21 | Cylinder Group-Ripper Lift | 1 |
| 3G***22 | Cylinder Group-Ripper Lift | 1 |
9j4537 Ripper Arrangement--Single Shank--Type 2
| 1U***01 | Lines Group-Attachment; Attachment Lines Group | 1 |
| 1U***73 | Cylinder Group | 1 |
| 3G***20 | Cylinder Group-Ripper Tilt | 2 |
9j4537 Ripper Arrangement--Single Shank--Type 1
| 3G***20 | Cylinder Group-Ripper Tilt | 2 |
| 3G***21 | Cylinder Group-Ripper Lift | 1 |
| 3G***22 | Cylinder Group-Ripper Lift | 1 |
3g5560 Ripper Group
| 3G***60 | Ripper Group; Ripper Group | 1 |
3g5555 Ripper Group
| 3G***55 | Ripper Group; Ripper Group | 1 |
3g9668 Control Valve Group--Type 1
| 3G***68 | Valve Group-Control | 1 |
3g9668 Control Valve Group--Type 2
| 3G***68 | Valve Group-Control | 1 |
10 serial number reference
The Ten's serial number is stamped into castings rather than shown on a bolt-on PIN plate: check the curved left side of the engine block just below the No. 1 cylinder, the left side of the transmission case just behind the left steering-clutch lever, or the right-hand radiator support near the headlight mount. Read it as the two-letter prefix PT followed by the sequential unit number (e.g. PT 202); unlike later Cat PIN formats there is no third prefix character, so use the PT-number-to-year production ranges to date the machine and inspect track gauge and final-drive details in person to confirm narrow, wide, or high-crop configuration.
| Prefix | Identifies | Notes |
|---|---|---|
| PT | Standard/narrow-gauge track-type tractor (Caterpillar Ten) | Two-letter prefix PT covers the entire Ten model line; there is no additional letter for plant or sub-series. Serial run starts at PT1 (December 1928) and ends around PT4929-PT4932 (late 1932 into 1933), roughly 4,900 units total. Approximate year breaks: PT1-PT7 (1928), PT8-PT3173 (1929, the peak production year), PT3174-PT4606 (1930), PT4607-PT4751 (1931), PT4752-PT4929/4932 (1932-33). Built at the Peoria, Illinois plant. Engine is a Caterpillar-built 4-cylinder side-valve gasoline unit, 85.7 mm x 101.6 mm (3-3/8 in x 4 in) bore/stroke, 2.3 L (143 cu in) displacement, 1500 rpm; rated about 7.5 kW (10 hp) drawbar and 11 kW (15 hp) belt/brake, with independent test figures of roughly 11.1 kW (14.9 hp) drawbar and 13.5 kW (18.1 hp) belt. 3-speed gear transmission, 200 mm (8 in) track shoes, operating weight around 2,000 kg (4,420 lb). Paint changed from gray to Hi-Way Yellow in December 1931, useful for rough dating alongside the PT number. |
| PT | Wide-gauge configuration | Same PT prefix and numbering sequence as the standard Ten; wide-gauge units are set apart by wider track centers, about 1118 mm (44 in) versus the 940 mm (37 in) standard/narrow gauge, not by a different prefix. Some parts-book listings append a W suffix after the PT number to flag a wide-gauge build - confirm with dealer/club registry before relying on that suffix for identification. |
| PT | High Crop / high-clearance configuration | High-clearance (High Crop) Tens use the same PT serial sequence, built mostly in 1930 for row-crop farm work such as potatoes and cotton. Extra ground clearance comes from a modified final-drive casing with an added gear and a reversed crown wheel to keep correct rotation direction. Roughly 400 high-clearance units were built (estimates range from approximately 397 to 420), a small fraction of total Ten production. |
Frequently asked questions
What engine does the Caterpillar 10 use?
A Caterpillar-built 4-cylinder L-head (side-valve) gasoline engine displacing 2.3 L (143 cu in), with an 85.7 mm x 101.6 mm (3-3/8 in x 4 in) bore and stroke and a 1,500 rpm rated speed. Ignition is a Eisemann G4 magneto with an Ensign Bet-1 carburetor and oil-bath air cleaner. Caterpillar's own rating was about 10 drawbar / 14 belt hp; a 1929 Nebraska test recorded 10.10 drawbar hp and 15.26 belt hp on the same engine.
What is the Caterpillar 10's operating weight?
Operating weight runs 2,004 to 2,041 kg (4,420 to 4,500 lb) and varies by configuration and series. The standard narrow-gauge machine sits at the lighter end; wide-gauge and High Crop high-clearance variants run toward the top of that range.
What replaced the Caterpillar 10?
Caterpillar ended Ten production in 1933 without a direct badge-for-badge replacement in the modern sense. The closest continuation was the 'Little' Fifteen, introduced around 1932 on a similar chassis and sharing the Ten's 2.3 L engine block in one of its configurations, before Caterpillar's small-crawler lineup evolved further later in the 1930s. The Ten itself had replaced the earlier Caterpillar 2-Ton when it launched in 1928.
What 10 owners discuss
What do owners say about running a Caterpillar Ten on modern pump gasoline?
What ignition problems come up most often on the Ten?
What's the community consensus on the Ten's engine bottom end and babbitt bearings?
What track and undercarriage wear patterns are typical for a Ten?
What steering clutch issues should owners watch for?
How hard is it to find parts for a Caterpillar Ten today?
What should a buyer check before purchasing a used Caterpillar Ten?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
Need a specific 10 part?
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