Notice: Please push left button over 3 minitus to turn on monitor, if it does not work, please try again after charging. Parameter 1.Monitoring system body Operating voltage: 3.7-5V Storage temperature:-30C-90C working temperature:-30C-85C RF Emiion frequency:433.92MH50KHz RF Signal sensitivity:-90dbm Display mode:LCD Color Bright screen current:6mA Black screen current:4mA Size:85*95MM2. External Sensor Battery life:24 months Operating voltage:2.1-3.6V Storage temperature:-30C-90C working temperature:-30C-85C Temperature resolution:2C25C Preure range:0-3.5Bar Preure resolution:0.1Bar Waterproof grade:IP67 Transmitted power:10dBm Emiion frequency:433.92MHz Size:21mm*17mm weight:8.0g lithium battery:CR1632Model Features: Solar power charging; High and low preure, leak alarm; LCD display screen, Simple user interface High accuracy, Using Freescale imported chips; Real-time monitoring tire preure and temperature; Smart start: parking automatically sleep, the car starts automatically wake up. Two units(PSI / Bar) changeable, you can set the one you like. Sensors' battery Changeable Description: Solve the sensor does not work:Match sensor(Vent)