1. 2 in 1 Smart Car Safety System: GPS HUD & Vehicle Inclinometer 2. Plug & Play: Start with the car and turn off with car's engine off. 3. Easy installation: with car charging cable, can work on all vehicles. 4. Speed Unit:KM/H & MPH Switch freely. 5. Built-in high-precision GPS module with dual-channel satellites. Real-time display car's Speed,Voltage, also Attitude, Compass, Coordinates... Built-in Slope Sensor: for pitching angle, roll angle measurement. Different alarms: over-speed, over/high voltage, abnormal altitude, Fatigue driving, Tilt Angle Danger alarm, Pitch Angle Danger Alarm; Support Clock & Driving speed calibration Product Parameters: Supply: DC 10V ~ 30V Pitch Angle: -40~ +40 Time Error: less than 1minute Voltage Precision: 05V GPS Cold Start Duration: 32s( Average) GPS Update Rate: 1S Dimension: 127x25x60mm (L x W x H) Working Temperature: -40 +80 Roll Angle: -40~ +40 Voltage Range: DC 10V ~ 30V Speed Precision: less than 036Km/h GPS Hot Start Duration: 1s(Average) Wireless Transmission Frequency: 24GHz colour: black Material: ABS Package Contents: 1 x Main host 1 x Holder 1 x car charging cable 1 x English manual Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.