This drum fits 3500lbs axles with #84 spindles. Compatible with standard trailer axles from most manufacturers. Use with electric or hydraulic brakes. Fits import or domestic manufacturers of axles and braking components. Specs: Works with 10″x 2-1/4″ Brake assemblies Bolt pattern: 5 on 4.5″ Wheel studs: 1/2″ NF Grease cap diameter: 1.98″ Weight capacity: 1750 lbs Includes:Bearings, Races, Seal, wheel nuts and grease cap Parts Brake Down: Inner bearing: L68149 (1.375″ inner diameter) X 1 Outer bearing: L44649 (1.063″ inner diameter) X 1 Inner race: L68111 X 1 Outer race: L44610 X 1 Grease seal : 10-19 (2.565″ OD and 1.719″ ID, Double lip) X 1 Wheel Nuts: X1023R ( 1/2″ NF open ended) X 5 Grease Cap: 46749 X 1