'-SOLAR POWER & USB CHARGING]: 2 charging ways which ensure the tire pressure monitoring system will work continuously, and do not occupy the car lighter socket. -6 ALARM MODES]: fast leak alarm, slow leak alarm, high pressure alarm, high temperature alarm, sensor fault alarm and sensor battery low power alarm,  ensure safe driving. [ Press any button will stop alarming ] -DIGITAL LCD SCREEN]: the monitor displays real-time pressure & temperature, it can be placed anywhere stably and you can easily read the data. -EASY TO USE]: 4 wireless external sensors, easy installation and receive real-time signal. The pressure and temperature data can be switched (default 0- 3.5 Bar / 22- 87 Psi), with pressure unit: PSI/Bar and temperature unit: C/F selectable. -WIDELY USED]: TPMS is suitable for car tire pressure range less than 6.0 Bar, like sedans, SUV, MPV and etc. Note: If oone of the sensors does not work properly after first install, reinstall again and wait a short while, it will work then. Package Included: 1 X TPMS. 4 X External Sensor. 4 X Mounting Nut. 1 X Wrench. 1 X English User Manual