Size and Quantity: The metal lobster claw clasps are about 0.47x0.28x0.14 inch (12x7x3.5mm), hole: 0.06 inch (1.5mm), 100pcs. And the open jump rings are 0.20x0.02 inch (5x0.5mm), 24 Gauge, 300pcs. You can match them together to make various jewelry. Reliable Material: These necklace clasps and open jump rings are made of quality 304 stainless steel, durable and sturdy, not easy to break or fade, each clasp opens and closes easily and smoothly, which can serve you for a long-term use. Easy to Use: The lobster clasps and jump rings for jewelry making are easy to install. The open and closure of lobster clasps is smoothly and fit for most jump rings and chains, perfect for your homemade jewelry or repairing your existing jewelry. Wide Usage: The lobster clasps and jump rings are suitable for DIY projects and repairing, you can use them to complete your bracelets, necklaces, chains, pendants, earrings, anklets, hanging accessories and more, practical jewelry accessories for you. Make Sweet Gifts: You can complete your unique handiwork with these lobster clasps, and you can make exquisite finished jewelry for your family, friends, classmates or other important people during the holidays to express your care and love for them.