... of switch box ,junction box , 2.sizes: 3"x3" ,3"x6"20mm/ 25mm knockouts 3 color : white or black 1) name ... ,good insulation property,good fire-resistant3)Installation during the process of constuction ,electrical equipment ,components4)Easy to equipment ,long life ... wire and cable from easy damage11) Installation during the process of construction ,electrical equipment , components12)PVC 2 gang box are ...