Car HUD Speedometer OBD2 Diagnostic Tool with Real Time Speed Alerts for Safe Driving Universal Fit Features： 1、8 Major Display Switching: Vehicle speed/fuel consumption/acceleration time/water temperature/voltage/driving distance/driving time/Beijing time. 2、6 Alarm Functions: Overspeed alarm, RPM alarm, voltage alarm, water temperature alarm,fatigue driving alarm, fault code alarm. 3、Compact body, suitable for placement. No matter where it is placed, it is clear and natural, without blocking any line of sight. 4、The time can be automatically switched in combination with the speed of the vehicle, the speed is displayed when driving, and the time is displayed when waiting for traffic lights. 5、Hardware Upgrade:Using low-power chips, lossless standby completely solves the problem of high power consumption.Intelligent switch, start and close with the car. Specification： Features: 8 Major Display Switching: Vehicle speed/fuel consumption/acceleration time/water temperature/voltage/driving distance/driving time/Beijing time. 6 Alarm Functions: Overspeed alarm, RPM alarm, voltage alarm, water temperature alarm,fatigue driving alarm, fault code alarm. Hardware Upgrade: Using low-power chips, lossless standby completely solves the problem of high power consumption. Intelligent switch, start and close with the car. Brightness Upgrade: Fully automatic photosensitive, adaptive brightness adjustment, clear enough during the day, not dazzling at night. Software Upgrade: Add speed lubrication effect, no jump speed, more consistent and smooth display. Automatic Switch: Automatically turn on and off as the car starts and stops. Ingenious, every inch is carefully crafted, semicurved design, to make the shape of B2 more beautiful. Compact body, suitable for placement. No matter where it is placed, it is clear and natural, without blocking any line of sight. The time can be automatically switched in combination with the speed of the vehicle, the speed is displayed when driving, and the time is displayed when waiting for traffic lights. Note: OBDⅡ models apply to: OBDⅡ protocol gasoline cars produced after 2004 in the U.S. and OBDⅡ protocol gasoline cars produced after 2008 in other regions. Specifications: Color: Black Material: ABS Screen Size: 4inch System: OBDⅡ Product Size:128 * 36 * 25mm Package Weight: 140g Package Size: 14.3 * 9 * 5.1cm Package List: 1 * B2-Head Up Display Main Unit 1 * OBD Line 1 * Non-slip Doublesided Sticker  1 * User Manual Package List： 1 * B2-Head Up Display Main Unit 1 * OBD Line 1 * Non-slip Doublesided Sticker  1 * User Manual