Park the car on a level surface, stithe 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 signal until the data shows normal.and hold the setting on and clithe start on to adjust the electronic clock.Pre and hold the start on, and clithe setting on to adjust the time of the X90.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 40°the 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 meter starts automatically, after car parking the meter will be in sleep mode automatically.Over speed alarm.Fatigue driving alarm alerts after driving for 4 hoursPower: DC 10V~30VDepreion&Elevation angle: -40℃ +40℃CloError Value: Le than 1 minuteVoltage measurement accuracy: 0.5V Cold Boot Time: 32s (average) Data Refresh Time: 1sWorking Temperature: -40℃ ~ +80℃Roll Angle:-40℃ +40℃Voltage Measurement Range: DC5V~30VSpeed Accuracy: Le than 0.36Km/h Hot Boot Time: 1s (average)Wirele nsmiion Frequency:2.4GHzProduct Size:170x68x60(mm)Colour:blackMaterial:Plastic + PolycarbonatePackage Contents:1 x Head-up displayOnly the above package content, other products are not included.Note: Light reflection 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.