Wilwood's Tactical Extreme TX6R Big Brake rear kits are ultimate in braking performance for Truck, SUV and Armored Vehicles. Using TX6R radial mount six-piston calipers and massive 15.00" to 16.00" GT-60 directional vane Spec-37 alloy rotors, these kits deliver consistent stopping power and extreme duty durability under sustained high heat with this ready to bolt-on kit. The calipers are volume matched for compatibility with original equipment power brake system output. TX6R rear kits replace the factory disc brakes and use the OE parking brake assembly as a compliment to front big brake upgrades. Kits include radial mount caliper brackets, and all the necessary hardware to complete the installation. Braided stainless steel flex lines will need to be purchased for some applications.