[SOLAR POWER & USB CHARGING]: 2 charging ways which ensure the tire pressure monitoring system will work continuously, and do not occupy the car cigarette lighter socket. [6 ALARM MODES]: fast leak alarm, slow leak alarm, high pressure alarm, high temperature alarm, sensor fault alarm and sensor battery low power alarm, ensure safe driving. [ Press any button will stop alarming ] [DIGITAL LCD SCREEN]: the monitor displays real-time pressure & temperature, it can be placed anywhere stably and you can easily read the data. [EASY TO USE]: 4 wireless external sensors, easy installation and receive real-time signal. The pressure and temperature data can be switched (default 0.5- 3.5 Bar), with pressure unit: PSI/Bar and temperature unit: C/F selectable. TPMS receiver: -Battery: Built-in 400mAh lithium ion battery -Working voltage: DC 5V -RF transmission frequency: 433.92MHz -Pressure unit: psi / bar -Temperature unit: Deg.C / Deg.F. -Working temperature: minus 20 plus 85 degrees Celsius -Storage temperature: minus 40-plus 125 degrees Celsius Internal sensor: -Working pressure: 0-51 psi / 0-3.5 bar -Pressure accuracy: plus or minus 0.1BAR -Transmission frequency: 433.92MHz -Working temperature: minus 20-plus 85 degrees Celsius -Storage temperature: minus 40-plus 125 degrees Celsius -Working voltage: 2.0-3.6V -Waterproof rating: IP67 -Battery: Built-in CR24500 button battery -Battery life: 2-5 years (not replaceable, the sensor needs to be replaced when the battery is dead) External sensor: -Working pressure: 0-51 psi / 0-3.5 bar -Pressure accuracy: +/- 0.1BARi -Working frequency: 433.92MHz -Working voltage: 2.0-3.6V -Waterproof: IP67 -Working temperature: minus 40 plus 85 degrees Celsius -Storage temperature: minus 40-plus 125 degrees Celsius -Battery: Built-in CR1632 120mAh button battery -Battery life: 1-2 years (replaceable battery)