Installed in the wheels of a car to monitoring both tire pressure and temperature inside the rim of your tire. It is used to safely alert the driver of problems before complete tire failure. Receiver display (main unit): 1) Working voltage: 12V, car battery 2) Dimension: 120 x 66 x 40mm 3) Working temp.: -20 ~ 75 4) Working wireless freq.: 433.92mhz Sensor transmitter (secondary unit): 1) Working voltage: 3.6V, lithium battery 2) Dimension: 69 x 29 x 23mm 3) Working temp.: -40 ~ 125 4) Working wireless freq.: 433.92mhz 5) Pressure test range: 0 ~ 600kPa 6) Accuracy of pressure test: less than 0.05kg/cm2 7) Accuracy of temp. test: less than 3 8) Working life: 5 years 9) Weight of sensor: 32g