Wireless plug-in doorbell for single door applications. Features double 2-note melody and self-programming to avoid interference with other systems. Chime box plugs into any standard outlet and wireless push-button requires (1) CR2032 lithium battery, which is included. 3.25 inches wide x 4.25 inches high x 1.5 inches deep. Weighs 0.5 pounds 1 year warranty.