Race Ramps (RR-FS-10) 10" Wide Flatstopper (Pack of 4) Keeps tires from flat-spotting during long periods of storage Tires settle into the concave depression to prevent flat spots Never conducts heat or cold into your tires despite changing floor temperatures Won't slip, slide, or scoot on any surface and never scratches or marks your floors Fits tires up to 8" wide with a diameter up to 20"