all kinds of wall box ,flushing box , sizes: 3"x3" ,3"x6"20mm/ 25mm knockouts color : white material : pvc 1) name: ... 1 gang box,flushing box,wall box2) sizes: 3"x3",3"x6"box, 20mm/25mm knockouts3) material : pvc4) Uses : electrical ... biotic attack.2)Good insulation characteristic ,good insulation property,good fire-resistant3)Installation during the process of constuction ,electrical equipment ...