ISMR3000M 3.5 Inch Low Voltage IC Airtight New Construction Housing is designed for insulated new construction applications. IC designation allows insulation to be in direct contact with housing. Below ceiling accessible. Takes up to a 7/8 inch ceiling thickness. Low voltage 12 volt magnetic transformer included. One 20-50 watt, 12 volt GU5.3 MR16 bulb is required, but not included. Wattage dependent on housing/trim combination. Dimmable with a low voltage magnetic dimmer. Consult with bulb manufacturer for low voltage magnetic dimmer compatibility when using LED bulb option. Suitable for damp locations. UL listed. 3.75 inch ceiling cut out. 19.5 inch length x 10 inch width x 7.1 inch height. A complete fixture includes a housing and trim, sold separately.