Specifications and functions: -Solar power charging, No need to charge by connecting the car cigarette lighter-Colorful, Clear LCD Digital Screen to Show Tire Information-Control of preure and temperature of 4 tires in rear time-Low air preure / high temperature alarm-High temperature / leak / low battery alarm-Smart start when the car is moving, no need to turn on / off-Wirele connection by sensors, easy installation-Built-in sensors and external sensor options, meets all your needs-Freescale chip sensors and fit almost 98% cars on the market Built-in sensor (Optional): -Install in the profeional car center-More stable and accurate-Anti temperate and cold-IP67 protection / waterproof-Operating temperature: -40 -125 -Battery life: 5 years, replaceableExternal sensor (Optional):-Easy to install, convenient to replace-Dust-proof / waterproof / anti-theft-Anti temperate and cold-IP67 protection / waterproof-Operating temperature: -20 -80 -Battery life: 2 years, repl cable