HiPer's PROFill advantages are weight, superior cornering performance, ease of installation, affordability, and the ability to make quick adjustments for maximum suspension performance and traction. Weighing more than a half pound per wheel less than other flat prevention systems and unable to absorb water, PROFill gives riders increased performance. PROFill can be inflated through the normal valve stem and requires no special tools to tune tire pressures. PROFill eliminates the cornering chatter and vibration of other systems reducing rider fatigue while increasing cornering performance. To add more performance, PROFill is available in soft and hard compounds which can be mixed together for medium compounds tuned for the specific track and conditions. The PROFill system is available in ten inch front and nine inch rear combinations for cross country motocross desert WORCS racing. 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 Proprietary materials designed to achieve ultimate performance Tunable for maximum performance with soft and hard compounds Adjustable by air pressure, filled through standard wheel valve stem Designed for all 10” front tires and 9” rear tire applications Each box contains 28 pcs. to make 1 system per tire/wheel Soft compound: Harsh conditions like cross country Hard compound: Trail and less intense riding Alternate soft/hard per wheel for medium if both sets purchased