[SOLAR POWER & USB CHARGING]: 2 charging ways which ensure the tire preure monitoring system will work continuously, and do not occupy the car cigarette lighter socket. [6 ALARM MODES]: fast leak alarm, slow leak alarm, high preure alarm, high temperature alarm, sensor fault alarm and sensor battery low power alarm, ensure safe driving. [ Pre any button will stop alarming ] [DIGITAL LCD SCREEN]: the monitor displays real-time preure & temperature, it can be placed anywhere stably and you can easily read the data. [EASY TO USE]: 4 wirele external sensors, easy installation and receive real-time signal. The preure and temperature data can be switched (default 0.5- 3.5 Bar), with preure unit: PSI/Bar and temperature unit: C/F selectable. TPMS receiver: -Battery: Built-in 400mAh lithium ion battery-Working voltage: DC 5V-RF transmiion frequency: 433.92MHz-Preure unit: psi / bar-Temperature unit: Deg.C / Deg.F.-Working temperature: minus 20 plus 85 degrees Celsius-Storage temperature: minus 40-plus 125 degrees Celsiu Internal sensor: -Working preure: 0-51 psi / 0-3.5 bar-Preure accuracy: plus or minus 0.1BAR-Transmiion 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 preure: 0-51 psi / 0-3.5 bar-Preure 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)