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. This SS4+ Deep Stage system is the lightest weight version available, and is recommended for use with parachutes, and/or lighter weight vehicles. If you have a full weight S550, and rely more on brake alone the version 2.0 is recommended., , NOTE: This system comes equipped with a street compound pad that offers low noise and dust and are NOT suited for track use. Race compound pads are also available for track use, call for information., , | Rotor Size/Type:, 11.625" x .705", 2-piece, , | Replacement Rotor Rings:, 6910186 (Left) / 6920186 (Right), , | Caliper/Piston Count/Mount Type:, S4 / 4-piston / Lug, , | Replacement Pads:, 6070012 (Street), 6070012-S (Race) , , | Minimum Wheel Size:, 15" (Use template to verify fitment, link below), , | System Includes:, Calipers, Brake pads, 2pc rotors, Banjo bolts & washers (does not include hoses), , | Notes:, Designed to be used with 2015-2018 Ford Mustang S550 Front Spindles. , System weight - 28.1lbs, , | Applications:, - 2015-18 Mustang with OE spindles and hubs (Does not fit GT350)