Feature:1. Solar Charging Large area solar lighting board/ 17% conversion rate/ USB (Universal Serial Bus) interface.2. Smart Shock Boot TMPS will turn on when car moving & shock with shock boot. It doesnt need to turn on or thrn off by yourself.3. Built in sensor 4. Dust-Proof 5. Water-Proof 6. Anti High Temperature & Cold 7. Anti-rejection Fly 8. Anti-thief Specification: Working voltage: 2.1-3.5 V Pressure Accuracy: 7KPAFrequency: 433.92 MHz Pressure Rate: 0 KPA-400KPAPackage Included:1 XTire Pressure Monitor System