3 in 1 multifunctional and easy to use: This is a pressure gauge for precise monitoring of tire pressure. It also functions as a tire inflator when connected to an air compressor. Additionally, it features a built-in vent valve for quickly releasing pressure from overinflated tires. High accuracy: Professionally calibrated to provide readings within 1% of actual tire pressure with 0.1 PSI resolution. No more surprises. Measures accurately from 0 to 250 PSI (0-17.2 bar; 0-1724 kPa; 0-17.5 kgf/cm²). Waterproof design with automatic shut-off and valve extension. The quick-locking air line (push-fit gas interface) ensures a secure seal on the tire valve and allows hands-free operation while using a tire pump. Long service life: Constructed from high-quality stainless steel and brass components for durability. Suitable for use with all vehicles including cars, SUVs, trucks, motorcycles, and bicycles. Automatically turns on and off after 20 seconds of inactivity to conserve battery power. Integrated vent valve allows rapid pressure reduction in overfilled tires. High-quality construction: Noticeable weight due to premium materials. Built with durable stainless steel and brass to withstand pressures up to 250 PSI. Rubber hose is insulated and extra thick for reliable performance. High precision 250 PSI tire pressure gauge. Measuring range: 0-250 PSI. Accuracy: ±1% + 0.1 PSI. Displays in four units: PSI, BAR, KPA, KG/cm². Button functions: On/Off button (left), unit switch/LED light (right). Compatibility: 1/4 NPT air compressor connection (included). Operating voltage: DC 3.1 V (2 AAA batteries included). Instructions: 1. Remove the valve cap from the tire. 2. Attach the brass head of the gauge to the tire valve. 3. Read the displayed pressure. 4. Connect an air compressor hose to the inflator port and hold the handle to inflate or release air as needed. 5. After use, remove the gauge and press the bleed valve to reset the display to zero. Includes: 4 valve caps, 1 brass air chuck, 2 AAA batteries, 1 NPT steel fitting, 1 roll of thread sealing tape, 1 pneumatic rotary chuck, 2 O-ring sealing washers.