IT4000CM 3 Inch Low Voltage Non-IC Shallow Remodel Housing is designed for non insulated remodel applications. Non-IC designation requires that insulation be kept a minimum of 3 inches away from housing. Takes up to 7/8 inch ceiling thickness. Low voltage 12 volt magnetic transformer included. One 20 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 magnetic dimmer compatibility when using LED bulb option. Suitable for damp locations. UL listed. 3.25 inch ceiling cut out. 11.9 inch length x 4.25 inch width x 3.2 inch height. A complete fixture includes a housing and trim, sold separately.