USB or Solar Charging Car TPMS Tire Pressure Monitoring System HD Digital LCD Display Auto Alarm tool Wireless 4 internalSensor 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 Emission frequency:433.92MH50KHz RF Signal sensitivity:-90dbm Display mode:LCD Color Bright screen current:6mA Black screen current:4mA Size:85*95MM Features: Solar power charging; High and low pressure, leak alarm; LCD display screen, Simple user interface High accuracy, Using Freescale imported chips; Real-time monitoring tire pressure 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"'" batteryChangeable Description: Solve the sensor does not work:Match sensor(Vent) Long press menu key 3 seconds to U/S,then short press menu key several times to enterLID interface,it shows ID of four tires and car icon. Short press left/right select key to learn ID opertion.Select tire you plan to learn ID of sensor by pressmenu key,default setting is FL When tire is selected,display new ID in receiver after active sensor//"'"s ID(internal sensor active by charging/vent tier). Do the same operation to match other three sensor.When all sensor are matched,short press menu key to save and go to Ex. External Internal