This kit of trailer brake parts can be purchased to upgrade your existing YOLO Trailer with electric brakes. If upgrade kit is purchase along with a trailer we will install the brakes for you. Kit includes: (2) Trailer Hub & Drum Assembly for 3,500-lb Axles - 10" Diameter - 5 on 4-1/2: Features: Trailer hub-and-drum assembly provides surface area for brake shoes to grip when brake is activated Pre-greased hub is easy to install - no need to pack bearings Sturdy iron construction Bearings, races, grease seal, grease cap, wheel bolts, and lug nuts are included Hub and drum are made in the USA Specs: Application: 3,500-lb E-Z Lube trailer axles with #84 spindles Drum dimensions: 10" diameter x 2-1/4" wide Works with 10" brake assembly Bolt pattern: 5 on 4-1/2" Grease cap flange diameter: 1.986" Wheel bolt diameter: 1/2" Weight capacity: 3,500 lbs Bearing, Race, and Seal Information: Bearings (included) Inner bearing: L68149 (1.378" inner diameter) Outer bearing: L44649 (1.063" inner diameter) Races (included) Inner race: L68111 Outer race: L44610 Grease seal (included): 10-19 Inner diameter: 1.719" Outer diameter: 2.565" (1) Dexter Electric Trailer Brakes - 10" - Left/Right Hand Assemblies - 3.5K Features: Easier to install and gives you more control than hydraulic brakes Periodic manual adjustment required Can be done in minutes Long-lasting brake pads offer excellent braking torque Fully bonded to shoes for more consistent braking compared to riveted pads Adjuster plugs (included) protect internal components from dirt, grime, and road debris Left-hand (driver's-side) and right-hand (passenger's-side) brake assemblies included Includes mounting hardware Made in the USA Specs: Dimensions: 10" diameter x 2-1/4" wide Mounting flange bolt pattern: 4 bolt Mounting flange bolt hole distance: 2-7/8" apart on center Wheel size: 14", 14-1/2", and 15" Axle rating: 3,500 lbs Limited 5-year warranty