First Alert Parking Alert Sensor

Package: 1 EaEasily mounts on wall, workbench or shelf in garage Ultrasonic range-finding technology Uses 3 different light indicators with alert sound based on range from sensor On/off switch Powered by included 120V AC adapter or 9V battery (required) Includes mounting tape Display unit dim: 7.28"H x 2.4"W x 1.22"D Sensor dim: 3.23"H x 2.4"W x 1.46"D