Digital Car Gps Speedometer. Features: Head-up Display the Driving Speed Driving Time and Mileage Calculation and Display Easy Setup--Plug & Play- Power Through Vehicle Cigarette Lighter. No Professional Installation is Required. Compatible with All Cars & Trucks & Motorcycles and Bicycles. Use GPS Signal Guided Calculation. No Wiring Needed to the VSS (vehicle Speed Signal). Display MPH or KM/h  Auto Adjust Brightness Through Sensor for Day & Night Driving. Vehicle Driving Speed Display. Green Color Speed Display, Easy on Your Eye.  Over-speed Alarm Setting. Total Mileage Display After Car Stops. Altitude Display. Specifications: Material: ABS+PC Size: 150*59*16mm Screen Size Approx.101*55mm Input VoltageV5V Input Current DC 50-120mA Description: Set the Over-speed Alarm Rate Press the Up Button or Down Button to Increase or Decrease the Speed Rate The Default Alarm Speed Rate is 120KM/h Set Display Mode: Press Enter Button, You Will See Numbers 111 222 333 Are Shown on the Screen 111 Refers to Normal Display Mode, Content Will Be Shown on the Screen in Normal Condition. 222 Refer to Reflecting Display Mode, Content Will Be Shown on the Screen in Opposite Side in Order to Be Reflected On the Windscreen Correctly. 333 Refer to Upside-down Display Mode, Content Will Be Shown on the Screen Upside-down in Order to Fit the Specific Position in the Car, Such As Behind the Front Rearview Mirror. (for Certain Vehicle Models Only) Set the Speed Meter Unit (KM or Mile) Long Press the Enter Button, if You See Number 100 Shown on the Screen, Which Means KM/h Long Press the Enter Button, if You See Number 161 Shown on the Screen, Which Means MPH The Default Speed Meter Unit is Set As KM/h System Will Start Calculating Total Driving Time and Mileage when Device is Powered On. Parking Time is Not Included in the Calculations in Order to Increase the Data Accuracy. Mileage Less Than 1KM Will Be Considered As Invalid Data Once the Vehicle Stops for a Few Seconds, You Will See Data Displayed on the Screen in Order As Total Mileage, and then The All Driving Data Will Be Cleared Once the Vehicle is Engine Off, and System Will Start the Calculation Again when the Car In Every Hour, System Will Trigger a Fatigue Driving Alarm with Continuous Driving Time Displayed, in Order to Remind Driver To Example: 001 Means One-hour Continuous Driving, 002 Means Two-hour Continuous Driving and So On. Over Speed Alarm Set the over Speed Alarm Rate (As Described in the IV Operation Guide) A Three Times Beep Sound Alarm Will Be Triggered when over Speed Occurs. No More Alarm Will Be Triggered when Over-speed is Detected Continuously. . We are an international seller, your order will be shipped from abroad so please allow the necessary time of minimum 14 working days for delivery right now depending on where you ship to, due to ongoing delays in postal deliveries globally.