500 Pieces -- You will receive about 500 pcs open jump rings, these rings are about 4mm(1/6") in diameter, 0.7mm thick(21 Gauge), about 2.6mm inner diameter. Please check the size carefully before buying.304 Stainless Steel -- The surface is plated with 18K gold, Tarnish Free. The inside is solid 304 stainless steel jump rings, which will not fade easily, strong, shiny and durable, and will not easy to break or tarnish, thus can be used for a long time..How TO Attach -- You can use needle nose pliers/jewelry pliers. Grasp the ring on either side of the split. Slowly pull apart. You'll need to have a good grip before you pull. Use 1 plier to squeeze it closed..Wide Application -- You can use these jump rings and connectors to DIY delicate necklaces, bracelets, anklets, keychains, key ring pendants, or accessory decorations for cellphone, bags, purse..21 Gauge -- You can feel confident that your jewelry will stay together when you use these jump rings. They are small but the thickness of the jump rings are reliable.