(SERIES PP, ND): Die-cast aluminum housing with integral heat sinks. Housing interlocks and wraps around lens base producing maximum moisture deflection and resistance to prying. Standard bronze exterior TGIC polyester powder coat 5-step pre-treatment. (SERIES NL): 18-gauge CRS housing. Housing interlocks and wraps around lens base producing maximum moisture deflection and resistance to prying. Standard white exterior TGIC polyester powder coat 5-step pre-treatment.