Newhouse Hardware Two Note Electric Door Bell Chime, 16V/10 VA, Size: 7.2" x 4" x 2", White Classic Ding Dong sound Dimensions: 7.2 x 4 x 2 Use with a 16-volt/10 VA or 16-volt/15 VA transformer (not included). Search B019BW9VZ2 for a compatible transformer Please Note: This item does not include the door bell button or the transformer. Search B019BWA0ES for a door chime, transformer and door button set Please Note: The instruction manual may be inside the chime cover, which can be removed by gently using a flat head screwdriver on the 4" side.The instructions are available on this item page as a PDF file in the "Product Information" section under "Technical Specification" (the link to the file is "User Manual") Includes: Door Chime and mounting screws (found inside the chime cover).