Wilwood AERO4 Big Brake Rear Brake Kits replace the factory disc brakes and use the OE parking brake assembly as a compliment to front big brake upgrades on late model trucks and SUV’s. High capacity braking from the AERO4 calipers, BP-10 or BP-20 compound pads, and oversized rotors are matched to the OE master cylinder output, ABS function, and individual vehicle bias requirements. Enhanced brake performance, increased durability, and high-tech style compliment big wheel, tire, and suspension upgrades on customized vehicles, tow rigs, and all others with increased brake requirements from high gross vehicle weight.