The CRTW series provides serviceability from walkable composite ceilings. Installed within and supported by a finished composite ceiling system of thicknesses of 2, 3 or 4 inches. Rated for 800lbs static load without fixture damage. An overlapping gasketed door frame seals the room at the ceiling. Gaskets are also provided at the lens and top cover to prevent dust, liquid or vapor penetration. It is UL Listed for wet locations, cleanroom rated ISO-3, certified dust tight and water resistant to IP65 for frequent rigorous cleaning practices. Tested according to ASTM-72 and E2322 for strength and load resistance.