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.