We are offering junction boxes.Metal : pig iron ironmalleablefinishes : hot dipp, electro galvanised and black enameldescription : 60.3mm internal diameter x 25.4mm deep tapped m4 in mm sizes and 2ba in imperial sizes of 50.3mm with tapped hole in base for earthing screw.Supplied without covers & screw unless ordered.Size (mm) 20mm, 25mm, 32mm, 38mm, 50mm