This tire inflator gauge includes tire inflator and deflator, Operating pressure 0-8 Bar, 2-1/2 in. large dial mechanical air pressure gauge, 13.78 in. long maximum pressure rubber hose, brass straight chuck with leak free valve core. It is a complete 3 in 1 function tool ready for testing tire pressure, deflating and inflating tire with air pump or compressor (not included). Tire inflators can easily inflate tires, extend tire life, save fuel, and ensure driving safety. An air inflator pressure relief gauge reduces tooling and simplifies the restart process. Please be sure to use when the tires are cold, and regularly use the tire pressure gauge to measure the tire pressure, especially before long trips to avoid possible tire problems on the road. It can attach inline to your air compressor (not included) hose through the 1/4 in. NPT fittings. The side buttons can be used for easier inflation work. It is suitable for truck, UTV, ATV, bus, RV, car, motorcycle and bike (with Schrader valve). No battery needed.