Unit start up OK. But can't detect and movements. Is the sensor not working or main control unit not work? Can feel the sensor is warm so there is power to the sensor. Can not find the dip switches that you can change the detection speed. Any warranty on this unit? No comments on the supplier service yet till they reply my complains. ***** Please ignore the above complains. Because I did not set it up properly so it is not working. This unit calculates the relative speed of your auto with the adjacent auto so it is important to set it up in your auto and do a driving test. Thanks for the supplier's help (Robert Li). This unit is a DIY project because it is easy to install. No deed to drill any hole. Excellent BSD design, quality & service.

very good product