This is a nice set of clean,  newest design AP monoblock, solid bridge, internally plumbed, AP Radi-Cal race calipers w/ 4 piston (stainless alloy) differential bore 26mm / 30mm
for 300mm-325mm x 25mm-32mm rotors. Part #CP5420. Pad shape PFC #7735, 7736 / AP 5510D43  This set has been race prep'd and rebuilt w/ new seals, pistons & bleeders.
Very light weight, very rigid. New cost over 2k each!