Note: When you receive the package and turn on the receiver, the receiver displays "--" or "00", please contact me as soon as poible or 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. Specifications. Material: ABSProduct Size: 12*6.3*2.5CMOperating frequency: 433.92MHZWorking voltage: 3.7V~5VOperating current: 6MAUSB charging current: 250MADormant current: 4MAStorage temperature: -30~90Operating temperature: -30~+85Monitoring temperature range: -40~130Air preure range: 0~3. 5BarAccuracy: 0.1BarNumber of sensors: 4PCSSensor type: built-in/externalCharging method: Solar/USBDisplay battery capacity: 650mAhDisplay function: tire preure, temperature, clock, calendar display screen rotates360 degrees freely upgrade the large screen display, tire preure, temperature, time, calendar can be the same screen display, easy to watch, easy to understand more information solar and USB two charging methods to improve the working time of the tire preure, the use will also be more convenient a variety of alarm modes, air leakage / high preure / high temperature / low battery alarm function, at any time to understand the tire preure situation, to improve the safety of driving with the car start function, the display will follow the car start or standstill to automatically turn on or hibernate. No manual operation, use more intelligent, reduce power consumption rotatable bracket, multi-angle adjustment of the installation position, to meet more installation needs, can be installed in the front windshield or instrument panel Day and night as clear as before you will worry about traveling is it like thi do it yourself 3 minutes to complete