Single Strand Round Barrel ClaspRound barrel clasps are a secure choice for jewelry, commonly used to fasten chain ends together. They feature a threading mechanism, utilizing a hook or screw, which opens and closes with a twist. Available in various sizes to fit a variety of pieces, they may not be ideal for bracelets as they require two hands to operate. Sold by an individual, Finished: Semi Polished, Size Ring ID 8. 5 x 2 mm 1. 3 mm 8. 5 x 3 mm 1. 3 mm 8. 5 x 4 mm 1. 7 mm