A pair of 40mm effective length threaded valve extensions for use with removable valve core presta valves allows deep section rims to be converted to tubeless use by way of external threads for securing the presta nut the only externally threaded valve extenders on the marketfeaturescnc machined aluminum valve extension 2 grams eachrubber o ring seals inside the valve to eliminate leaksadds 40mm of length to any removable core presta valvecan be used with our road tubeless valvecan be used