Carlon 72-3196 Carlon Wireless Corner Chime Features include: Up to 150-foot operating range Different sounds for front and back doors (add buttons for extra doors) 32 selectable codes block interference from outside signals Compatible with all Carlon wireless chime systems only (Note: Not compatible with Carlon wireless doorbell systems) Six sound options Fits neatly against walls Measures 525 x 675 x 8-Inch Chime requires four C-cell batteries (not included)Door chime button requires two 3-Volt batteries (installed)