The Fail-Safe CFD Cleanroom Troffer is enclosed and gasketed to maintain ceiling integrity and protect against infiltration of particles and airborne bacteria. The 2x4 housing and door is suitable with 1" inverted T-Grid ceilings. Specify the 15T option for 1 ½” T-grids. 2x2 and 1x4 are standard with 1” and 1 ½” T-grids. The sealed, hole-free housing prevents air exchange between the fixture and plenum and allows re-lamping without contamination of clean areas. UL/cUL listed for wet locations for covered ceiling applications.