Associated accessories WC8420 Aluminium outer casing for plasterboard - 264 mm WC8421 Aluminium outer casing for plasterboard - 514 mm WC8422 Aluminium outer casing for plasterboard - 1014 mm WC8423 Aluminium outer casing for plasterboard - 1515 mm WC8424 Aluminium outer casing for plasterboard - 2015 mm