This system features the 4-piston, S4 caliper mounted to a 12in x 1.100in 2 piece?slotted?rotor and uses the popular DR1/HB100 pad type.?Slot onlyrotors are mounted to 6061 billet aluminum hats using NAS high grade stainless hardware and come pre-assembled. All additional mounting hardware is also included.?The SS4+ 2.0 Deep Stage system was designed to allow consumers to push the limits at the strip, yet still have a system that can be driven on the street. The SS4+ 2.0 Deep Stage system fits many 15in and larger wheels.?NOTE?This system comes equipped with a high friction pad that is optimized for drag race applications. These pads often produce more dust and noise. Drag Race systems come standard in Clear and Fire Red caliper colors.