Safety Beam is a high tech device which creates an invisible infrared beam up to 60 feet long and sounds a loud alarm or pleasant chime when the beam is crossed. Retail stores and businesses can use the one chime feature to announce customers entering the store or the continuous chime to alert them when someone enters an "off limits" area (in this mode the chime sounds continuously until you turn it off). The continuous chime mode is also good for alerting you when a child leaves a safe area. Not only can it be used as an invisible playpen to alert you when your child or pet leaves a safe area, it can also be used at night to scare off intruders.