Know instantly if someone has entered your store or property, even if you're not within line of sight. The IR Entry Alert System is an easy-to-use chime alert that emits a "ding-dong" or siren sound when the kit's included beam is interrupted. Ideal for use as an entry detection system for a store or as a safety sensor for garage doors, this kit sets up in seconds for easy alert. With a range of up to 22 feet, the retro-reflective photoelectric sensor signals the chime unit instantly when its wide path is crossed. The chime's speaker volume can be adjusted or turned off with the flip of a switch, and in siren mode, the sounding time is adjustable from 3 to 30 seconds. Unlike many door chime systems, there's no hardwiring required to install the IR Entry Alert System: All components simply plug into one another, and mounting brackets and a power adapter are included in the kit.