S&B0 236 WNG-PLL Surface Mounted Luminaire 2x36w Housing High quality cold-rolled steel sheet of thickness 0.6 (T6) Louver Spring-lock type louver for ease of maintenance. Lamp Holder Heavy duty rotary-locked type (TIS.344-1987 Standard) , Rptary-lockedd type starter holder (TIS Standard) fot T8 lamp IP Rating IP20