50 piece pack of charlotte crimps (also known as carlotte crimps, bead tips, clam shell crimps, crimp covers and clamshell knot concealers), diameter of cover: 4mm, length of loop: 4mm (total length: 8mm). Used to conceal knots/crimps in necklaces - thread through the small hole in the side of the crimp, finish off your necklace with a knot or standard crimp and cut off any excess wire/string. Close the cover and join the loop onto a clasp etc. These charlotte crimps aren't suitable for heavy necklaces/bracelets. Available in bright silver, bright gold, black, bronze, dark silver (nickel) or copper.