Cupchain connector was designed specifically to accommodate 4mm cupchain. Simply add a dab of glue to secure, place cupchain in connector, push down then bend 2 prongs over with pliers. Connector can also fit other types of cube beads smaller than 4mm in size.
Chain Terminator>Gold Plated/Finished>Gold ColoredFindings and Components>Terminators>Chain TerminatorGold Plated/FinishedGold Coloredhttp://www.firemountaingems.com/itemdetails/h20a6174fnH20A6174FNConnector, gold-finished brass, 4.5x4.5mm, fits 4mm cupchain. Sold per pkg of 50.//image1.fmgstatic.com/images/pa6174fnb.jpg6.426.42As Low As $0.06 per connector