Foldable Car TPMS Tire Preure Monitoring System LCD Display Solar Power Digital TMPS Auto Security Alarm Tire Preure Sensor 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