Entry Alert Beam Chime / Alarm - Invisible Beam Alert 671

You can know when someone "crosses the line". This high tech device creates an invisible infrared beam up to 60 ft. long between the two units. When the beam is crossed a loud alarm or a pleasant chime sound will be emitted. Can be used as an invisible playpen to alert you to your child or pet leaving a safe area. The alarm can also be used at night to scare off would-be intruders. In the chime mode, retail stores in businesses can use it to announce customers and alert them when someone enters an area that is "off limits". You can choose to have the chime sound only one time (when a customer enters a store for example) or the chime can sound continuously until you turn it off (when a customer enters an area that is "off limits" or at home when a child leaves a safe area for example). Distance can be sent to high or low - maximum distance between units is 60 ft. In the chime mode, volume can be set to low, medium, or high. NOTE: both units have included AC adapters and must face each other; the invisible beam or line is between the two units. Only one of the units sounds an alert. Two AC adapters are included. Three AA back-up (only) batteries are not included.

Notes:
- Receiver and Transmitter face each other.
- Both units plug-in to 110VAC on each side of entry way.
- One unit sounds alert signal. http://www.entryalertproducts.com/product/entry-alert-beam-chime-alarm-invisible-beam-alert-671/