The fine pore, silk-like to the touch, Grand Prix Cover is perfect for fine particle sand conditions. It has elastic around the bottom of the cover that allows it to sit perfectly around the air filter, preventing fine particles entering the filter and in turn your engine. The Cover will act as an additional layer of protection and extend service time between filter cleaning. GRAND PRIX COVER YZ250F 14-18 YZ450F 14-18 WR250F 15-18 WR450F 15-18 GRAND PRIX COVER - (POWERFLOW KIT ONLY ) YAMAHA YZ250F 19-23 YZ450F 18-22