10 PCS 3/4/5mm Coil Cord Spring Necklace Bracelet Leather Ends Cap Connectors Size details are shown in the photos Colors: Silver, Gold, Antique Brass Size in Diameter x Length: 3mm x 7mm, 4mm x 10mm, 5mm x 10mm what do I do with these? Create a neat finish to mesh chain, rubber, leather and waxed cotton cords. Simply insert the chain or cord into the coil and use pliers to twist and compress the first coil around the chainor cord for a tight, secure hold. Use the already made loop at the end for attaching jump rings/clasps.