Why You Need TPMS? Using pressure monitoring sensors within each tire to monitor to specific pressure levels. Powered by solar energy and LCD display, it lets driver get the real-time tire pressure data, temperature data and status, warning messages at once.   Features: Real-time Monitoring: LCD display shows the pressure and temperature of 4 tires simultaneously, letting driver get real-time information about the tire condition.  Two Charge Methods: Large solar panel, quick charge, also including USB connector charge.  Intelligent Alarm: Leakage Alert, High Temperature Alert, High Pressure Alert, Low Pressure Alert.  Multiple Information: Including sensor/display's battery capacity display, solar energy charging display, spare tire display.  Effective Protection: 4 internal sensors with anti-corrosion, anti-off technology, high-quality tire pressure sensors are stable to ensure your driving safety.   Specifications: Install Way: Internal;  Display Way: Screen;  Sensor Working Voltage: 2 - 3.6V;  Display working Voltage: 3.5 - 4.2V;  Optional Pressure Units: Psi/Bar;  Optional Temperature Units: Deg.C, Deg.F;  Operating Frequency: 433.92MHz +/- 20KHz;  Sensor Working Temperature: -40 Deg.C - 125 Deg.C;  Display Working Temperature: -40 Deg.C - 85 Deg.C;  Monitoring Temperature Scope: -40 Deg.C - 85 Deg.C;  Monitoring Pressure Scope: 0 - 5 Bar;  Display Battery Capacity: 800mAh;  Sensor Battery Supply: CR2050 battery;  Sensor Battery Capacity: 345mAh;  Package Size: 20.50*14.50*6.00cm / 8.07*5.71*2.36in;  Package Weight: 400g / 14.1oz;  4 * TPMS;  1 * Displayer;  1 * Non-slip Mat;  4 * Screw;  1 * User Manual