This system features the 4-piston, S4 caliper mounted to a 11.62″ x .705″ 2 piece slot, drill, zinc plated rotor and uses the popular HB540 pad type. Rotors are pre-assembled with NAS high grade stainless hardware. Mounting hardware is also included. The SS4+ Deep Stage system is the first drag race system designed specifically for heavy, fast cars that might also see street use. The SS4+ Deep Stage system fits most 15” and larger wheels.