1.all kinds of switch box ,junction box , 2.sizes: 3"x3" ,3"x6"20mm/ 25mm knockouts ... gang box,flushing box,surface box,wall box , cable box ,junction box 2) sizes: 3"x3",3"x6"box, 20mm/25mm ... )2 gang box are used as surface mounting control box , junction box or general service box7)switch box protects wire and ... or general service box square 3x3 surface box/ cable box/ junction box