It is the automobile parks or time the back-draftsafe auxiliary unit, (popular name pokes head in), the controller bythe ultrasonic sensor and the monitor (or buzzer) and so on partiallyis composed.

• 它是汽车泊车或者倒车时的安全辅助装置，由超声波传感器（俗称探头）、控制器和显示器（或蜂鸣器）等部分组成。