Valve
Valve: a valve is the mechanism used for inflating an inner tube. A pump is clipped or screwed onto the valve an air enters the tube. The valve can also be used to release air from your inner tubes. The three main types in use are Schrader valve, marked A in the picture(automotive type), Presta valve, marked S (high pressure type) and Woods valve, Marked D. Valves come in different lengths to accommodate different depth of wheel rim.
Tutorials
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