A 3" aperture specification grade adjustable housing platform that accepts 60W maximum line voltage tungsten-halogen lamps. Suitable for 2x10 residential framing or commercial installation. The platform is airtight to prevent energy loss, room drafts, dust marks on ceilings and reduce sound transmission. Units may be used in direct contact with insulation and building products. A complete fixture requires two components; a P3120 housing platform and a 3" optical element. Elements may be changed after installation to provide a variety of distributions.