Sometimes there's just not enough space around the tire's valve stem for the gas station air chuck and hose to reach. Brake rotors, sprockets and saddlebags get in the way and keep the air chuck from making an airtight seal. When that happens, this Valve Stem Extension provides easy access. Simply screw the extension in place on the stem, fill the tire to the proper pressure, remove the extension, and replace the valve stem cap. Then toss the extension in your saddlebag or tool roll for the next time.