Stainless steel ball chain, #10 size (bead diameter of .175 inch or 4.5 mm). Matching Stainless Steel #10 'B' Couplings are used as connectors for this chain and are included with this product. This product is genuine Ball Chain direct from the manufacturer - Ball Chain Manufacturing in Mount Vernon, NY - which means that it is made in the USA and is the most cost effective chain on the market. Ball Chain is used for many applications, including: dog tag chains, beaded chains, wholesale jewelry chains, badge chains, pull chain, industrial chain, vertical blind chain, retaining chain, plumbing chain, keychains, beaded lanyards, ID chain, and many more applications. Ball Chain Manufacturing is ISO 9001:2008 certified by the International Organization for Standardization and is also recognized by the Green Business Bureau as a certified green business". Ball Chain Manufacturing is the largest manufacturer of Ball Chain in the world and the only company that manufactures its chain in the United States. Our chain is everywhere, and our quality is second to none. Don't settle for low quality overseas imitations. Whatever the application, this chain will last.