12.25 In. x 4 In. Electric Trailer Brake Left & Right Kit 10,000 lbs Axle CapacityThe 4" wide brake padding and 10,000 lbs. capacity per pair is made for heavier duty, non marine applications. This brake uses a forward self adjusting feature which adjusts the brakes on each forward stop. As the shoes wear on the drums, the adjuster arm rotates the screw assembly at the bottom of the brake and expands the shoes. This will provide efficient braking power each time and less stress on the tow vehicle. Product Features: One left hand