This Drag Race Only system features four of the 4-piston, S4 caliper mounted to a 11" 2 piece slot, drill, zinc plated rotor. The S4 caliper has D.O.T compliant dust and weather seals and uses the popular DR1 or HB100 pad type. Rotors are pre-assembled with NAS high grade stainless hardware. Mounting brackets and hardware are also included. The SS4+ Deep Stage system is the first drag race system designed specifically for heavy, fast cars that rely on their brake to launch or stage the car. With 1.375" pistons, this system has been a very popular option in classes such as NMRA True Street where the cars could see limited street use. The 11" SS4+ Deep Stage system fits most 15” and larger wheels. This system was designed for racing only. If used on the street (due to brake bias change) be sure to spend some time to make sure adjusted correctly.