Topeak presta valve extenderthe topeak presta valve extender is machined from aircraft aluminium and features a rubber seal to stop air leaking from the tube features machined aircraft aluminium alloy with black anodised finish rubber seal to prevent high air pressure leakage size lxwxh 17 x 03 x 03 weight 34 gramsbuytopeak wheels tyresfrom chain reaction cycles the worlds largest online bike store