"Three in one multifunctional and easy to use: it is a tire pressure gauge, which can accurately monitor tire pressure; it is also a tire inflator, which can inflate tires when connected to a air compressor. Plus, it has a built-in deflation valve that quickly reduces pressure on over-inflated tires. High Accuracy: Professionally calibrated to always give you a reading within 1% of the exact tire pressure and 0.1 on the notch. more surprises Accurately measures 0-250 PSI (0-17.2 Bar; 0-1724 Kpa; 0-17.5 kgf/cm)Waterproof shut-off chuck and valve extender: Quick Lock Air Chuck (gas plug) provides a good seal on the tire valve on the outside of the car tire, allowing your hands to operate the tire pump.LONG LIFE: Manufactured from high quality and robust stainless steel and brass components for a very long life. Can be used on all vehicles such as cars, SUVs, trucks, motorcycles, bicycles, etc.Easy to use: automatically turns on and off after 20 seconds of inactivity to protect your battery ; the built-in deflation valve quickly reduces the pressure of overinflated tires. Product Description high-quality construction The first thing you notice about this gauge is its weight; Only high quality stainless steel and brass are used to provide an extremely robust gas filled gauge that can withstand pressures up to 250 PSI. The rubber hose is insulated and extra thick for excellent performance. 250PSI High Precision Tire Inflator Measurement Range: 0-250PSI Accuracy: (1% + 0.1psi) Four ranges: PSI, BAR, KPA, KG/CM^2 Key function: on/off key (left), switch/LED key (right) Compatibility: compressor connector air 1/4" NPT (included) Operating voltage: DC 3.1V (2 AAA batteries not included) how to use: 1. Unscrew the tire valve knot. 2. Connect the copper head of the meter to the valve 3. The device will display the pressure. 4. You need to find an inflation pump and a hose to connect the inflation mouthpiece and hold the handle of the product. When the pressure is low, it is inflated through the inflator and vice versa. 5. After the measurement, unscrew the copper head and press the vent hole to set the indicator to 0. All suitable accessories: 4 Beanies 1 x Brass Pneumatic Chuck 1 x "" NPT Steel Fitting 1 x Roll of Mesh Tape 1 x pneumatic torsion chuck 2 sealing washers