NuTone LA205WH Compact Contemporary Design Portable Wireless Door Chime, White Compact, contemporary design Receiver mounts on wall or can be placed on table Reliable operation and great sound -- Sounds two notes at one door only Installs in just minutes - no wires to run Receiver requires 3 AA batteries (not included) 2-3/4-Inch wide x 4-1/4-Inch high x 1-Inch deep