NHIC-4LMRAT 4" LED Dedicated IC Air-Tight New Construction Housing 4″ IC Air-Tight Dedicated New Construction housings are designed for use with all 4″ Nora Lighting LED retrofit luminares. IC housings are high-quality, lightweight units ideal for use in insulated ceilings. Airtight construction reduces energy costs by reducing the amount of air escaping through the ceiling. Rated for direct contact with insulation (except spray foam insulation) and combustive materials, Nora IC housings are easy and quick to install.