This wireless tyre Solar Charging TPMS is supplied with 4 external sensors and a digital monitor to monitor the tyre voltage and temperature of your vehicle 24-hour every day, and it also has a clock function.   Features: By using the advanced 4-in-1 wireless sensors that highly integrated pressure and temperature sensor we offer the top of the line and reliable TPMS for you.  Automatic solar charging, using higher quality and more durable solar lithium battery panels, which can extend the use time and help focus driving.  The intuitive monitor and smart buzzer secure a safer driving experience for you.  Real-time detection of tire pressure/temperature, battery power, leakage / low battery alarm. Instant audio alarm of abnormal pressure or temperature.  Wireless connect by sensors, easy installation.  LCD display screen, simple user interface. Sleep mode available.   Specifications: Input Voltage: 3.7 V~5V（USB）;  Sleep current: ≤4mA;  USB charging current: ≤250mA;  Working Temperature: -30℃ ～ 85℃;  Working Frequency: 433.92 MHz;  Monitoring Temperature range: -40℃~130℃;  Monitoring Air pressure range: 0~3.5Bar;  Product size: 93*51*27mm;  Battery: External Sensor CR1632(140mAh) / Solar lithium battery 3.7V 500mAh;  Package size: 16*14*6cm;  Packge weight: 280g;   Pakage list: 1 set Solar Charging Tyre Pressure Monitoring System