... "20mm/ 25mm knockouts color : white Square stamping conduit box 1) name:switch box, 2 gang box , 1 gang box,flushing box,surface box2) sizes: 3"x3 ... ,control box , switch box or general service box 3x3 box , pvc material . 200pcs/outer packing 3x6 box , pvc material ,200pcs/outer packing square 3x3 surface box/ cable box