Step on the pump, there are two air inlets on the pipe. If you inflate a car tire, the way to block the other air inlet is as follows. First, when the air pump is used to inflate the automobile tires, the atmospheric interface is connected, and then the pedal is pressed to inflate. The pressure gauge can be observed according to the different pressures required by the inflatable articles. Accurately measure the required pressure value of automobile tires. Because of the simple mechanical principle of two one-way valves and one cylinder, you can't breathe by blocking one of them with your hands.