4" linear system with industry-best combination of optics, energy efficiency and visual continuity within entire P40 series. Budget-friendly steel housing. Choose from one of Prudential's Premium Colors with no set-up fee. See their Bionic Series for the same great optics with a robust extruded aluminum housing. 3x 2015 IES Progress Report award winner for Wall Wash, Wall Graze and Ceiling Wash optics.