Solve the problem of having to run wires with STI’s commercial-grade Wireless Musical Chimes. They are quick and easy to install, with no electrical wiring and no expensive through-the-wall drilling. All units offer an exceptional operating range of up to 500 ft. between transmitter and receiver. Because they are compatible, multiple transmitters can link to the same receiver. Distinguish between front and back doors by selecting a different chime on each. They are UL/cUL listed, and FCC certified. The chimes let users know when the door opens or a person enters a detection zone. The chimes are available in four different models.