12-1/4x3-3/8" 9K 10K GD Electric Backing Plate 10000 Trailer Brake Left Side (BK-10KE-01)

Features 
-Self Adjusting! (Nev-R-Just)
- typical brakes for axles 8,000 to 10,000#
- This assembly uses a 7 bolt mounting pattern that should match your trailer axle. 
           (will not fit older 4 bolt mounts!) 
- Includes all hardware, including yellow wire magnet
           (You will need 1 pair to do one axle, 2 to do 2 axles, etc)

Technical Information
- There is a pair of lead wires attached to the brake magnet. One is ground and one is power. It doesn't matter which one you use in either location as long as they are attached properly. 

  - The way the brake assembly functions is there is a magnet that will apply friction to the lever in return pushes the shoes out into the drum causing friction which allows your trailer to come to a easy stop.