For mounting Paul flat mount calipers to flat mount frames and forks Front adapter can be flipped for use with either 140mm or 160mm rotors Rear adapter is for running 160mm rotors on a 140mm frame. It could also work for putting a 140 rotor on a 120 frame, or a 180 rotor on a 160 frame Mounting screws in various lengths for frames. 59mm of protruding thread is necessary for correct installment of the caliper