The High Output In-Duct DC UV air cleaners are designed to attach to air ducts and the UV lamps inserted in the air ducts. DC air cleaners are constructed of high grade stainless steel, utilizing two or four high output germicidal UV lamps. The DC UV fixtures are available in 120/230/277V, 50/60Hz. Please, specify voltage when ordering. All DC air cleaners use SBL high output germicidal UV lamps effective for 17,000 hours.