STI STI-3350 Wireless Doorbell Chime with Receiver, White by Safety Technology InternationalThis musical wireless doorbell chime is easy to install, with no electrical wiring and no expensive through-the-wall drilling. Installation is as easy as mounting the button on the exterior of the door and plugging the receiver unit into any indoor electrical outlet in range. To extend coverage to more rooms, purchase additional receiver units that can be plugged into any room within 500' (line of sight) of the transmitter.Distinguish between front and back doors by adding more transmitters (doorbell button) and programming a different tune on each.There are ten sounds that can be selected with the push of a button on each transmitter. Unit is UL/cUL Listed, FCC certified.
