This system features the S4 4-piston caliper mounted to an 11", 2-piece slot, drill, and 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. Baer’s unique backing plate not only acts as a caliper mount but is also the bearing retainer. Stainless braided hoses are also included. This system DOES NOT have a parking brake. The 11” SS4+ fits most 15” or larger wheels. Axle flange max diameter of 5.75". Comes standard with 5x4.5" and 5x4.75" bolt circle.