On Jun 16, 1:03*pm, Larry Jaques
wrote:

And I saw this $20 special in the recent HF ad:http://www.harborfreight.com/cpi/cta...emnumber=93068

Put 2 strips of tape over the right and left edges of the IR detector
to limit it to a narrower area of detection. It will cover the full
height of the garage door automatically.

The rounded piece is an infrared motion detector, the larger part its
remote receiver & alarm. If you mount the detector behind the garage
door track it would mask the garage interior and only view the door
opening. They work pretty well, but the chime sound becomes annoying
quickly.