The GP320 System features Wilwood’s competition proven dynamic rotor mount system, specially treated Super Alloy lightweight steel alloy rotors, and the highly efficient clamping force of the GP320 billet caliper for the most positive and fade-free performance available for sprint racing.Component Features: GP 320 Billet Aluminum 4 Piston Calipers with Four small pistons provide balanced distribution of the pad load for improved response and longer pad wear. Super Alloy Rotors: Unlike ceramic coatings that can flake away from the base metal during high heat cycling, Wilwood’s Super Alloy material controls heat transfer and provides a durable surface that can generate high friction for long, trouble-free duty cycles without the need for recoating. Dynamic mounting with Wilwood’s t-nut system isolates all thermal stress and distortion at the rotor mounting points caused by the different temperatures and expansion rates between the lightweight alloy steel rotor and the aluminum rotor mount plate. The rotors stay flatter and run truer to eliminate any possibility of pad knock-back or deflection. Dynamic Mount Rotor Plate: Lightweight billet alloy plate is machined with the slots to accept the rotor bolt t-nuts and adapt the rotor directly to 3 bolt sprint hubs. Wilwood 6211-CM Brake Pads A rigid caliper mounting bracket with premium grade fasteners and shim washers are included for secure, deflection free mounting.