Plug → Go: Speedometer is powered by a secure obd (on-board diagnostics) cable. USB version is universal, and uses GPS to determine speed. Multifunction: can display vehicle speed, water temperature, voltage, single mileage. Ready to Ride: Speedometer works with any vehicle that has an OBDor a USB port – including cars, trucks, motorcycles, bicycles, and boats. Night + Day: digital holographic display speedometer is visible during sunny days, and dark nights. Widely Application: With alarm function, overspeed alarm, water temperature alarm, voltage alarm, fatigue driving reminder HOW DOES WORK? Use included USB cable to connect device to your car, or an external power source. Configure device to your liking using included manual. Place device on your dashboard in front your steering wheel and up against windshield. digital display will reflect up onto glass, and create a "holographic" effect showing your speed! WHAT IS POWERED BY? HoloMeter is powered using included USB cable that you can plug into your car, or externally using a portable power bank. DOES WORK IN DAY? Yes! HoloMeter works both during day when sun is out, and at night when is dark! PACKAGE LIST: 1 * Holographic Speedometer NOTES: 1.Please kindly allow minor size differences due to manual measurement 2.Photo color might be a little different from actual product due to color display different monitors