2 packs Material: black + gray brass + orange rubber + gray roof prism, bak4 material, size: black + gray, about 8cm long, about 3.5cm diameter, about 1cm error [easy to use]: When the valve is in the closed position, insert a US valve fitting and twist to lock in place. Remove the connector cover and connect the standard electric pump. Since it takes time to inflate the compressor / tire pump, it is recommended to manually inflate the circuit board until it is difficult to inflate, then use an adapter to supplement the pressure. [Fast Inflation]: This inflatable sup valve adapter is easy to convert and has high inflation efficiency. Recommended PSI is easily achieved in 5-10 minutes using a compressor or tire pump. 【Lightweight and Portable】: It is precision made, precision engineered and easy to use. Lightweight and portable, separately packaged and sealed, easy to use and carry. 【Universal valve adapter】: the blade does not need a special air pump, the adapter can connect the inflation hose common to the blade. It is widely used in various canoes, kayaks, paddles, inflatable boats, etc.