This system features the S4 4-piston caliper mounted to a 12", 1 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. Baer's unique backing plate not only acts as a caliper mount, but also houses a modern 1-piece park brake shoe assembly. Stainless braided hoses are also included. The 12" SS4 fits most 16" or larger wheels. | Rotor Size/Type: 12" x 1.020", 1-piece | Replacement Rotors: 6910150 (Left) / 6920150 (Right) | Caliper/Piston Count/Mount Type: S4 / 4-piston / Lug | Replacement pads: DR1-C | Minimum Wheel Size: Some 15" or larger (Use template to verify fitment, link below) | System Includes: Calipers, Brake pads, Rotors, Brackets, Park brake assembly w/cables, Stainless braided brake hoses & system hardware. System incorporates Baer's unique Verislide design allowing the calipers to float with the factory c-clip axles | Notes: Designed to be used with small flange GM 10/12 bolt C-clip rear end | Applications: - 1964-77 GM A-Body cars with 10/12 bolt C-clip rear end