DNA 4-Piston Rear Brake Caliper Kit, Chrome. Aftermarket wide glide front ends, Choppers, Bobbers, etc. High performance 4-piston brake caliper made by DNA. Brackets made by DB2, in the US - made from single piece of billet aluminum. Includes spacers & axle reducer for 3/4" or 1" axle. Billet aluminum has better strength to weight ratio compared to cast aluminum. The design causes equalizing of the heat distribution throughout the brake pad to rotor interface, which in turn provides optimum friction dynamics. In addition, the differential bore ratio and total volumetric displacement ...