The X91 TPMS Smart Slope Meter perfectly combines the TPMS tire preure monitoring system, GPS car head-up display, and the on-board slope meter, which greatly improves the safety escort level and provide a more convenient using experience for users, also widely favored by a large number of off-road enthusiasts. X91 Slope Meter Features : 1.TPMS tire preure monitoring function: X91 is designed with TPMS tire preure monitoring function, which allows to monitor various conditions of tires, like the preure, temperature and abnormal alarm functions of four tires at the same time. 2.Slope meter function: Real-time measurement of vehicle rolling angle and pitch angle. Accurately display the downhill/uphill and left/right inclination value and equipped with over-slope alarm. 3.Accuracy positioning system: Equipped with a high-precision dual-channel satellite GPS signal module, which can locate the current position of the vehicle, provide latitude and longitude, vehicle speed, altitude and precise For compa direction, and no longer get lost while driving. 4.Color HD LCD Display: Adjust the screen brightne through the light intensity sensed by the light source sensor. Color HD LCD screen design with high resolution. Day and night, can be displayed in high definition. Installation Steps Park the car on a level surface and stick the back adhesive to fix it somewhere with easy vision, and manually adjust it to the horizontal level. Then connect the power supply to receive the satellite GPS signal until each data display is normal before driving.Exterior Sensor Installation(See pictures). Specifications: Power Supply: DC 10V ~ 30V Pitch Angle: -40~ +40 Time Error: Voltage Precision: 0.5V GPS Cold Start Duration: 32s Average GPS Update Rate: 1S Dimension: 70*59*59 (mm) Working Temperature: -40 +80 Roll Angle: -40~ +40 Voltage Range: DC 5V ~ 30V Speed Precision: GPS Start Duration: 1s(Average) Wirele Transmiion Frequency: 2.4GHz Weight: 603g Packing List 1pcs * X91 TPMS Smart Slope Meter Main unit 1pcs* Cigare Lighter 4pcs* External Tire Preure Sensor 1set* Screw Tool 1pcs* Manual