NW2000CM 4 Inch Low Voltage Non-IC Shallow New Construction Housing is a thermally protected housing designed for non-insulated new construction applications. Non-IC designation requires that insulation be kept a minimum of 3 inches away from housing. Below ceiling accessible. Takes up to 7/8 inch ceiling thickness. Low voltage 12 volt magnetic transformer is included. One 50 watt, 12 volt GU5.3 MR16 bulb is required, but not included. Dimmable with a low voltage magnetic dimmer. Consult bulb manufacturer for low voltage dimmer compatibility when using LED bulb option. 4.25 inch ceiling cut out. 14.5 inch length x 10 inch width x 3.5 inch height. A complete fixture includes a housing and trim, sold separately.