These 10mm jump rings have already been soldered closed for you. A larger sized Jump ring for terminating necklaces, bracelets and anklets strung on beading wire. Just loop each end of the wire around one of these and crimp - your wire can never come off of this closed ring. You can even tie beading cord around one of these rings for a quick and dirty termination. A little drop of glue or nail polish will hold the knot. Attach the clasp of your choice to the ring. The additional flexibility given by placing this extra ring between the clasp and the cord will reduce stress and breakage, too. Silver Plating over Brass. Measurements: 10mm outside diameter. Wire is 18 gauge, or .040 Inch. Quantity: 20 jump rings. This item is LEAD-FREE.