This is a nice set of clean, narrow speedway design AP  billet aluminum, removable bridge, internally plumbed, radial mount, race calipers w/ 4 piston (coated aluminum alloy) differential bore 44mm / 48mm
zero drag design for 300mm-320mm x 25mm-32mm rotors. Part #CP5835. Pad shape PFC #7700 / AP 2279D50  This set has been race prep'd (dyno) but never raced. Very light weight, very rigid. These
have larger pistons (more clamping power) than the comparable model from Brembo. New cost over $2200 each!