Smart TPMS Car Tire Preure Monitoring System Solar Digital LCD Display 4 Wheel Internal External Security Alarm Tyre Sensor Note: 1, When you receive the package and turn on the receiver, the receiver displays "--" or "00", please don't worry.You only need to mount the sensor on the tire, wait for about 1 minute, and you will see the display shows the preure and temperature of the tire.2, Only external sensors can replace battery, internal sensors can't replace battery. Features: 1. Real time Monitor tire preure can improve fuel efficiency, prolong tire life, increase traffic safety and monitor temperature.2. LCD displays tire preure and temperature3. Visual and sound warning4. Air leakage warning, low preure warning, high preure warning5. High temperature warning, low power warning and no signal warning6. Solar power for normal use. Available USB charge for sunle day7. Intelligent Shock Boot when car moving, don't need to turn on/off8. Wirele connect by sensors, easy install9. Build-in sensors and external sensors options, meets all your need10.Two units (PSI / Bar) changeable, you can set the one you like. Main unit Working Temp.: -2 ~ 75 C / 28~167 FStorage Temp.: -3~80 C / 26~176 FBattery: Built-in 400mAh batteryCharge Time: About 1h by DC 5V 1AWorking Voltage: DC 3.7-5V External sensor : Working Frequency: 433.92MHz 50KHzWorking Preure: 0-60Psi 2 PsiTransmit Frequency: 433.92MHzSensor IP: IP67Working Voltage: 2.1-3.6V;Working Temp.: -40~90 C / -40~194 FStorage Temp.: -40~100 C / -40-212 FBattery: Each sensor is powered by 1 x CR1632 lithium-ion battery (included) Internal sensor Working Frequency: 433.92MHz 50KHzSensor Working Preure: 0-60Psi 2 PsiNote: For car only )Sensor Transmit Frequency: 433.92MHzSensor IP: IP67Working Voltage: Sensor: 2.1-3.6VSensor Working Temp.: -40~90 C / -40~194 FSensor Storage Temp.: -40~100 C / -40-212 FSensor Battery: Included Package picture