Optex TD20U Wireless 2000 Motion Transmitter
The Optex TD20U is the wireless sensing mechanism that is used with the Optex RC-20U receiver. The beam is selectable and you can have a 17 foot fan pattern or a 50 foot straight, line of sight, beam. When someone or something breaks the beam of this "eye" detector it sends a signal back to the RC-20U which, in turn, produces an alert tone.
You can have up to 9 TD20U units paired with one RC-20U receiver. Make sure all areas outside of the home are covered with this great piece of equipment from Optex.