The Multi-Valve consists of two Boston valves with different thread patterns and a Shraeder valve with cap. One of these Boston valves is sure to fit your inflatable. Square base is much easier to turn than a round base, especially with wet hands. Shraeder valve allows you to inflate your towables quickly at a gas station or with an air compressor. Valve 1 measures 0.6"D x 0.9" diameter. Valve 2 measures 0.7"D x 0.8" diameter. | Airhead Multi-Valve for Inflatables | The House