Ultrasonic sensor parking alert ; Sensor detects distance of car from wall ; Yellow & red indicator lights tell when ;to slow down & stop ; Features ultrasonic, range-finding ;technology ; Choose from 3 stop zones â 1, 2 & 3 ft ; 1-year battery life; Requires 4 AA batteries;Works so well I have 2 of them in my garage I installed the first one about 2 months ago and found it works very well, so I added one for the other car in the garage several weeks ago. When you get about 5 feet from the sensor the red light starts flashing, which is the hint to slow down. You set a switch on the back of the sensor for 1, 2 or 3 feet, which is the when the light changes to a solid red. Some reviewers said they had a problem with trying to use 2 units in the same garage, because if the units are too close together, both units might sense the same car entering and would send signals that interfere with each other. The way I tested to see if this would be a problem before I ordered the 2nd unit is by noting that when I brought the 2nd car into the garage (on the side w/o the sensor) I noted that the installed sensor in front of the other car did not flash. This told me the sensors could be installed far enough apart that they would only "sense" the car immediately in front of it. Great product!!
