» Was redesigned with a cast backing plate in May 2000 replacing the stamped version. Fits Dexter 15,000lb axles(with cast backing and 7 bolt flange). For use with a 12 1/4" inside diameter and 5" deep drum. Left hand(driver's side).Complete assembly ready to install. To determine the size of the brake, you need 2 measurements. The first is the diameter of the brake(D). The second is the width of the shoe(W). It is good to take note of how many mounting bolts the brake has.