FEATURES REAL TIME DISPLAY + MULTIPLE ALARMS - With an LCD display that shows the exact real time pressure or temperature of 4 tires at the same time. Visual warning lights and audible alarms are immediately triggered in case of abnormal conditions. The alarm values can be adjusted as needed (default value is 29-44PSI). CIGARETTE PLUG SAVES SPACE - Powered by a cigarette plug, it consumes less power and takes up less space in the car. Simply plug in and install the external tire pressure sensor, you can always know the condition of your tires and ensure driving safety. WATERPROOF & LONG LIFE - Equipped with 4 advanced external tire pressure sensors. Each tire pressure sensor is mini-sized (9 grams), anti-theft, waterproof,and has a battery life of up to 2 years. Batteries are replaceable when exhausted. VERSATILE AND EASY TO INSTALL - This tire pressure monitoring system works with most four-tire vehicles. Simply mount the sensor to the tire the sensor is programmed and no programming is required for installation. MULTI-FUNCTIONAL DEVICE- Adjustable screen brightness for clearer display in different environments. External USB port to your phone. So whether you're parking in the sun or charging your phone in the garage, it stays charged. SPEC Material: ‎High-performance polymer or lightweight metal alloy Receiving frequency: 433.92MHZ 0.02MHZ Power off current: ≤100MA Operating temperature: -20°C85°C Operating current: 15MA Charging: USB+solar charging Working voltage: 3.7V Package Included: 1*Wireless Tire Pressure Monitoring System (TPMS) for Automobiles NOTES Ensure stems are compatible (rubber or metal). Avoid over-tightening sensors to preserve integrity.