The Track4 system comes with the 2-piece 4-piston, T4 caliper mounted to a 13", 1 piece slot, drill, zinc plated rotor. The T4 caliper has D.O.T compliant dust and weather seals and uses the popular D0749 pad type. All mounting brackets, stainless braided hoses and hardware are also included. The 13" Track4 is designed to fit most 17” or larger wheels. Fits 1960-87 Chevy/GMC 2WD 1/2 Ton Trucks w/Wilwood C10 Aluminum Modular Pro Spindles