Product Description: X90 is a smart GPS multi-functional horizontal speedometer for driving, fully supports high-precision monitoring of car speed,vehicle tilt angle, vehicle pitch angle changes, compa, time and car battery voltage status, to ensure your driving safety. Feature: Applicable to Asian cars, American cars, European cars. Equipped with high-precision satellite GPS signal module. Automatically monitor vehicle driving conditions. Adjust the brightne of the screen by using the sensitivity of the light sensor. Free rotation, which is more sensitive. It adopts color HD LCD display with high resolution. Function: Precisely shows vehicle tilt angle with clear notification, when the angle is over 40, alarm alerts. Precisely show vehicle pitch angle changes,when the angle is over 40the alarm alerts to insure your safety. After connected to power supply, there will be backlight inside, which will help you see accurately in case of night or dark situation. Elevation error within 5- 100 meters. After the vehicle starts the speedometer starts automatically, after car parking the meter will be in sleep mode automatically. Over speed alarm. Fatigue driving alarm alerts after driving for 4 hour Specification: Power: DC 10V~30V Depreion&Elevation angle: -40 +40 Clock Error Value: < 1 minute Voltage measurement accuracy: O.5V GPS Cold Boot Time: 32s (average) GPS Data Refresh Time: 1 Working Temperature: -40 ~ +80 Roll Angle:-40 +40 Voltage Measurement Range: DC5V~30V Speed Accuracy: < 0.36Km/h GPS Hot Boot Time: 1s (average) Wirele Transmiion Frequency:2.4GHz Product Size:170*68*60(mm) Instruction: Park the car on a level surface, stick the adhesive on the product, adjust and fix it in the vehicle for easy horizontal view. Before driving, connect the power supply and wait to receive the satellite GPS signal until the data shows normal. Long and hold the setting button and click the start button to adjust the electronic clock. Pre and hold the start button, and click the setting button to adjust the time of the X90. Package Included: 1*X90 HUD 1*Cigare lighter 1*Fixed pad 1*Instruction manual 1*Packing box How To Switch From Miles To Km? it supports both MPH/h and KM/h Pre M , switch MPH/h inch and KM/h metric (Note: Altitude is in feet in MPH/h mode and meters in KM/h mode) (Explanation: MPH/h lights up to MPH/h Mode, MPH/h is off to indicate KM/h mode) How to adjust the time? In the state of power off, pre the power button. After the screen lights up, pre and hold the M button / power button 3-4 seconds immediately 1. Decrease time: Long pre the M key will automatically enter the time adjustment interface. M key (left): adjust the hour hand, power button (on the right): adjust the second hand. 2. Add time: long pre the power button. some country's time is slower /faster than GPS time some hour You can adjust time according to the user manual