About GPS HUD: Features: Elegant appearance,large screen and clear fonts. Multi-functionsa.Driving speed display. b. Compa display.Compa direction is the driving direction. c.Over-speed alarm. d.Fatigue driving alarm. e.Single driving mileage display f. Single driving time display. Driving speed unit can be switched between MPH and KM/H. Below data can be calibrated/adjusted: a.Driving speed. b.Over-speed alarm rate. The case is made of high temperature resistant anti-fire materials, it will not be deformed at 80 degrees for 3 hours, tested by a profeional high temperature machine. No built-in battery, no explosion/no burning hazard under high temperature. Compatible with all Cars &Trucks.Use GPS signal guided calculation,No wiring needed to the VSS(vehicle speed signal). Easy setup--Plug & Play, No profeional installation is required. Specifications: Input voltage: DC 5.0V. Input current: >150mA Working temperature:-30 to 80 C (-22 to 176 F). Working humidity: 20%~85%. Driving data deviation is around 2%. Fits for:Universal For All Vehicles Colour: Black Size: As the picture show GPS positioning time:1 to 5 minutes in the open air (The bad weather will affect the positioning time).There is no GPS signals indoors. Speed deviation: Since the speed data comes f om the GPS satellite,slightdeviation is unavoidable. Package included: 1x HUD Speedometer 1x USB Cable 1X Holder 1x User Manual About Y03 HUD: Functions: GPS and Beidou dual chips, the speedometer is very accurate, and the speed is refreshed quickly without any delay. Innovative design, with sunshine hood itself, good review even under sun. Plug & Play, after connect power supply, it will work directly, no need any other operation. Large font, clearly visible both during the day and at night. Speed unit is KMH (not support MPH). Wide application, it can work on all cars, trucks, buses, E-scooters, E-bikes. TheDevice is GPS Digital Speedometer, and speed is collected fromsatellites. So if tested at home or parking lot, perhaps speed can'tdisplay correctly. Please test it on the car outside with good signal. Note: it's speed display ONLY, no other function. Specification: Model: Y03 Screen Size: 2.8 Inch Material: ABS+PC Screen Type: LED Applicable models: Universal for most vehicles Color: Black and Green Package Included: 1 x HUD 1 x Micro USB Cable 1 x Manual Do drop