2005-2010 Jeep Grand Cherokee WK or Commander XH Rear Big Brake Kit. This kit uses a Wilwood FNSL4R calipers and WK SRT8 rotors. This kit includes SRT8 rear backing plates to mount the caliper bracket and calipers. Greatly improves stopping distances and eliminates brake fade during extreme braking conditions. Includes: FNSL4R Calipers, SRT8 rear backing plates, machined aluminum radial mounts, BP10 brake pads, stainless steel brake hose, and all hardware. Must be used with 20 inch wheels. Will not work with 17" wheels. Rotors not included. This kit is made to order, expect 2-4 week lead time.