Plug and Play: After connecting to the power supply, it can work directly without any other operation 10Hz Refresh: No jumping speed, the display is more coherent and smooth GPS+Beidou Dual Chip: Very accurate speed measurement, fast speed refresh screen display: big font, multiple functions Auto Dimming: Clearly visible day and night Speed unit:KM/H and can be changed freely Note:This device is a GPS digital speedometer, and the speed is collected from satellites Colour:Black Material:Plastic Package Contents: 1 set * heads-up display Only 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.