This system features the 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. Billet aluminum hubs come assembled with premium bearings packed with Redline synthetic grease and billet dust caps. All mounting brackets and hardware are also included. The 13" Track4 is designed to fit most 17" or larger wheels.