The Edwards pull cord switch provides emergency call activation. Calls are placed by pulling one of the attached 6 ft cords. Cords are replaceable with a standard nylon cord. Designed for either flush or surface mounting. Unit fits in a standard 1-gang electrical box and plaster cover. For surface mounting, use a Wiremold surface box. All boxes must have a minimum depth of 1-3/4 in. Boxes and covers not supplied.