You’d be amazed at the dirt and debris that can end up in your fuel carrier and then into your fuel tank. Twin Air’s monofilament screen pocket inserts into your fuel tank and catches the particles as small as 40 microns (.00165”) while allowing the gas to flow freely. The flange is custom-sized for each modern 4-stroke model to ensure a leak-proof seal. Just remove the filter periodically, turn inside out, and clean the debris that could have been in your engine. FUEL FILTER - 160262 YAMAHA YZ250FX 16-19 YZ450FX 17-18 WR250F 16-19 WR450F 16-19