Product Features: Safety : Automatically display speed information on windscreen to shorten driver's eyesight off the road. Speed warning : Provides warning signal and alarm when vehicle travels over setup speed limit, signal can be adjusted according to speed limit. Easy installation : Simply plug the power cable into the power outlet in your vehicle, the unit will setup automatically when power is on. Special function : The embedded GPS module can act as navigational satelite receiver (varies by models) and transmit information to other device such as laptop or PDA. Specification: GS-800 HUD Specification- Operating Voltage : DC5V ± 5% Adaptor Power In : DC12~24V Power Consumption : 450mA Operating Temp. : -20C~85C Speed Ranges : 0~255km/h Max. Brightness : 5500 nit Driving Speed Display : Green Speeding Warning Sign : Red KM/h / MPH icon : Green Dimension : 100.7mm x 91.4mm x 26.5mm GPS Module- GPS Chipset : SiRF Star III Frenquency : 1575.42MHz (L1 band, CA code) Channels : 20 channels Accuracy : 2DRMS: approx. 10m TTFF : Cold Start: 42s / Warm Start: 38s / Hot Start: 1s. White box with color sleeve.