Marine grade aluminum. Extruded body with die-cast end caps. Housing, with end caps, post assembly TGIC polyester powder coat finished 5-step pre-treatment. See Ordering Information for standard, optional, architectural and custom finishes. Each linear run of luminaires consists of one Beginning of Run Luminaire (B), one or multiple Middle Luminaire(s) (M), and one End of Run Luminaire (E). Specify and/or order systems per linear run (i.e. (1)B48, (5)M48, (1)E48). NOTE: Contact factory for custom lengths.