... 1.all kinds of switch box ,junction box , 2.sizes: 3"x3" ,3"x6"20mm/ 25mm knockouts 3 color : white or black 1 ... good insulation property,good fire-resistant3)Installation during the process of constuction ,electrical equipment ,components4)Easy to equipment ,long life ... easy damage8)Installation during the process of construction ,equipment, component9) PVC 2 gang box, 1 gang box with no smell ...