"3 in 1 multi-function and easy to use: it is a tire pressure gauge to accurately monitor tire pressure; It is also a tire inflator for inflating tires when connecting an air compressor. In addition, it has a built-in air bleeder valve that quickly lowers the pressure of overinflated tires.High Accuracy: Professionally calibrated to always give you a reading within 1% of your exact tire pressure and 0.1 on display. More surprises Accurately measures from 0 to 250 PSI (0-17.2 Bar; 0-1724 Kpa; 0-17.5 kgf/cm)WATERPROOF S S CHUCK & VALVE EXPANDER: Quick lock air chuck (socket gas interface) provides great sealing on the tire valve outside of the car tire and releases your hands to operate the tire pump.Long lifespan: Made of high quality and robust stainless steel and brass components to give it a very long lifespan. Can be used with all vehicles, such as car, SUV, truck, motorcycle, bicycle, etc.Easy to use: turns on and off automatically after 20 seconds of inactivity to preserve your battery; built-in air bleeder valve to quickly reduce pressure in overinflated tyres.Product High quality constructionThe first thing you'll notice about this gauge is its weight; only high quality stainless steel and brass have been used to provide an extremely sturdy inflation gauge that can withstand up to 250 PSI. The rubber hose is insulated and extra thick for superior performance. 250PSI HIGH PRECISION TIRE INFLATION GAUGEMeasuring range: 0-250PSIAccuracy: (1%+0.1PSI)Four ranges: PSI, BAR, KPA, KG/CM^2Key Function: On/Off Key(Left), Switch/LED Key(Right)Compatibility: 1/4" NPT Air Compressor Connector (Included) Operating voltage: DC 3.1V (2 AAA batteries included) How to use: 1. Unscrew the tire valve knot. 2. Attach the copper head of the gauge to the valve3. The device will show the pressure. 4. You need to find an inflatable gas pump and hose to connect the inflatable mouthpiece and hold the handle of the product. Inflate it through the inflatorwhen the pressure is low or vice versa. 5.After measurement, unscrew the copper head and press the air vent to make the indicator 0. All Appropriate Accessories: 4 x Valve Caps1 x Brass Air Chuck2 x AAA Battery1 x ""NPT Steel Fitting1 x Roll of Threaded Joint Tape1 x Pneumatic Twist Chuck2 x Sealing washers O"