23.0 Cu. In. 4" dia. round fixture support box for use with nonmetallic sheathed cable - Machine tapped fixture holes -New work residential construction 2 HR fire resistive walls and ceilings (50 lbs. fixture support) - Polycarbonate - thermoplastic box with galvanized adjustable stabilizer bar Depth=2 15/16", Dia=4" - Mount with Adjustable bar hanger - 16" to 24" on center joist application