Precision CNC-machined chromed billet aluminum construction Features differential bore technology, stainless steel pistons and chrome hardware Quick-change design for easy pad maintenance Dual, hidden bleeder for easy bleeding Made in the U.S.A. For use with custom 13" rotors only. For replacement pads, see 1721-2455 or 1720-0215.. CALIPER 6P 13"RTR BLK