Rated IP66; Suitable for ISO 3-9 Cleanspaces; Suitable for 209E class 1-100,000 Cleanspaces; ETL listed for Wet Locations; One piece overlapping doorframe; Robotically seam welded housing; Service to luminare from Plenum Side of ceiling; Made in the USA by a Family Owned US Corporation; This KURTZON product is illuminated by BIOS to provide healthy, low energy lighting that promotes improved sleep, better health and well-being