... of switch box ,flushing box , sizes: 3"x3" ,3"x6"20mm/ 25mm knockouts color : white material : pvc ) name:swithc box, 2 gang box , 1 gang box,flushing box2 ... process of construction ,electrical equipment , components12)PVC 2 gang box are used as surface mounting ,control box , switch box or general service box pvc conduit surface switch box