Spring Ring Clasp 5mm w/ Closed Ring Gold Filled (1-Pc) Simple and reliable, our 5mm Gold Filled Spring Rings are made from heavy tubing to help retain proper shape and alignment, and feature strong inner springs for reliability and security. The Jump Rings are soldered closed, for a more secure attachment to Necklaces and Bracelets. Size: 5mm Jump Ring: 2.5mm (closed)