Please note!!! When you receive the package and turn onthe 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. Main Features:-Solar power charging, LCD color displaying, adjustable brightne-Rear-time monitoring the preure & temperature-Low air preure/high temperature warning-Set up sensor: learn new sensor ID code when replace sensor-Two units (PSI / Bar) changeable, you can set the one you like.-Preure value:about 0-4 barReceiver Specification: Solar power charging LCD display Adhere to windscreen for installation Operating frequency: 433.92Mhz 50KHz Operating voltage: 3.7-5 V Working temperature: -20 C -75 C 1+1 charging modeSolar charging +USB charging Suitable for many kinds of carsSuitable for Cars, ORV, SUV, MPV, Minibus, Wagon, etc. Intelligent On and OffWhen the car is started, the vibration of the machine is automatically opened and the machineis shut down automatically when it is still, without manual operation. Sensor Specification: Operating frequency: 433.92MhzWorking temperature: -40 C -120 C Humidity: 0% to 100% Battery life:External sensor> 2 years/ 30,000 km Working preure: 0 58Psi Alarm preure: >46.5Psi or Q: What is TPMS?A: It is Tire Preure Monitoring System and also call Tire Preure Sensor. Make alarm and show car tires' preure and temperature.Q: How to install sensors?A: We suggest to install the build-in sensors by profeional car center; external one install can read our page and manual for reference.Q: Does the solar charging work for cloudy day?A: Yes. Normally, full solar charging can work for 3 days and it can work in cloudy and fog days.Q: Can it work in snow day?A: Yes. If the TPMS show "N5 Alarm", Please don't worry and just drive the car for a distance make tires moving. It will be ok. The external sensors will be affected by cold environment, just need to running cars.Q: Does it need to connect car cigarette lighter for charging?A: No. Normally it will charge by solar, but if you meet a very bad weather for a long time or need urgent charge, you can use the USB for charge. (USB not included)Q: Does it need to turn on/off the TPMS?A: No. It will turn on by shock boot and turn off if there is no shock for 10 minutes.