These barrel clasps have a built-in security screw which is very durable and easy to screw in. These screw clasps are great for repairing your existing jewelry or for creating homemade jewelry, necklaces, anklets, charm bracelets, or craft/fashion projects with ease. They have a beautiful and shiny look that keeps your jewelry shining. Each screw clasp measures approximately 4mm x 15mm. They are the perfect size. Each clasp has an open ring at each end. These jewelry clasps attach the ends of a necklace or bracelet together by screwing the two pieces together and forming the barrel shape. The color is silver.