Blue Demon BLUEARC-SPL-ADAPTER Universal Welding Wire Spool Adapter This universal welding wire spool adapter quickly adapts most wirefeeders and integrated MIG machines to use a 4 inch (1 or 2lb) spool. Promotes a smoother feed of wire due to its location to the wire inlet. The adapter allows the customer to use a 4 inch spool for small jobs and demontrations when the expense of a larger spool cannot be justified.