---Automatically engages as soon as you place your car into reverse. ---Embeded "bi.bi." buzzer and Left/Right tri-color lamp ---2 8 pieces different color sensors is available ---Easy installation, the mirror simply clips over the top of your existing mirror ---Power(DC): +9 +16 V ---Operation temperature available: -35 +75 degrees ---Human speaking warning is optional---Wireless version is optional:No need to run a wire from the front of the vehicle to the rear .If you have any question,please don't hesitate to contact me at any time on following Contact:ellen tao Mobile:+86-15818699729