The Wall Box Adapter Kit is designed to allow easy installation of wall mounted fixtures to standard USA 3/0 and 4/0 junction boxes. The kit includes a mounting strap and necessary screws. Available in Stainless Steel, Copper, or powder coat Black or Bronze. Supplied with Retro wall mounted fixtures, but must be ordered separately for 12 volt luminaires. Dimensions: 4.9 inch diameter x .1 inch depth.