Newest TPMS Solar Power Tyre Preure Monitoring System with 4 Sensors LCD Real-time Display Car Tire Preure Auto Alarm System 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