Tinksky 10pcs Presta to Schrader Bike Bicycle Pump Valve Adapters Connectors 10 pieces of the pump valve adapters connectors in one set will be sold together. Material: durable copper-plated zinc alloy and soft rubber. Size: Total length: about 1.5cm; Big head diameter: abou 0.9cm; Small head diameter: about 0.7cm. Can be used with a bike bicycle pump or an air compressor. Convert a Presta valve to a Schrader valve. Also turn a UK valve into a US valve.