Hiper Wheel Profill Tire Insert System - Rear - 9x9, 9x8 - Soft Compound PF-0911-SOFT An all-new tire insert system designed to improve overall vehicle performance with the security of a run-flat system Tested and proven on track in the GNCC series Engineered design for vibration free, faster cornering and stability Easier to install, easier to maintain Super lightweight at only 1.1 pounds per wheel