The D52 caliper is a direct bolt - on 2 piston replacement for the factory original single calipers on many 1968 - 96 GM Passenger Vehicles and Trucks. Forged billet aluminum bodies, stainless steel pistons, and competition style high - temperature seals put and end to the rust, bore pitting, and seal failures that plague the OE caliper design. D52 calipers provide low - maintenance performance and a huge weight savings with high temperature reliability for the street and track.