The TD-20U Indoor/Outdoor Sensor Transmitter from Optex offers two selectable detection patterns, a 17' fan pattern or a 50' beam pattern. The sensor uses PIR to detect motion, and once motion is detected it sends a signal back to the RC-20U Chime Box Receiver using RF signals. The device is powered by a standard 9V battery (available separately) which can last for approximately 2 years when the sensor is triggered about 250 times a day. There is a red LED that indicates when the sensor has detected motion and when the battery is low. Up to nine TD-20U units can be added to one RC-20U Receiver, enabling you to set up a full perimeter around your property.

When used with the 50' long-range detection pattern, the transmitter is suitable for applications such as driveways, entryways/walkways, warehouse delivery areas, constructions sites, art galleries, drive-up windows, delivery doors, and similar scenarios. When used with the 17' fan (wide) angle detection pattern, the transmitter can be used to monitor hard to see items, merchandise that is prone to shoplifting, inside display cases at jewelry stores, department store dressing rooms or fitting rooms, the unauthorized use of emergency exits, supply rooms or closets, and home or business entry points. With an IP54-rated housing, the sensor is suitable for use in outdoor areas for a wide range of applications.