Chicago plenum rated (CCEA) new construction housing for use in insulated ceilings can be in direct contact with insulation. Air-tight construction provides energy savings by reducing the flow of air through the ceiling. Patented design allows for easy, tool-less removal of the driver. Input Voltage: 120/277V Wattage: 24W Dimming: Phase (Triac or ELV) or 0-10V Ceiling Thickness: Up to 0.5in. Extension collar accessory for ceilings up to 2", ordered separately (NIO-4EXTC2) Compatible Trims: NIO-4PSTLA, NIO-4PSTLNDC Listing: cULus Listed for Damp Locations (Wet locations when used with compatible trim)