A. 304 BLACK STAINLESS STEEL – Our quick connectors are made of durable 309 stainless steel, which provides resistance to wear, corrosion and deformation. They can remain rust-free in wet, fresh or saltwater environments, ensuring long use. The polished surface is free of burrs, ensuring a secure and comfortable grip. B. EASY TO USE: The quick link chain connector features a screw lock. The threaded and hex nuts on both ends of the locking carabiner provide a certain level of security and stability. By turning the screw to lock, you can create a permanent or temporary secure connection that is user-friendly. C. MULTIPLE CHAIN QUICK CONNECTORS: These durable quick connectors are versatile accessories used in many applications. They are suitable for chain links, fence gates, swings, pet chains, sails, fitness equipment, DIY accessories or hanging a chandelier. Chain link connectors can also be used for outdoor activities such as camping, fishing, hiking, traveling, gazebo sails, carabiners, etc. D. PRODUCT SPECIFICATIONS - Our product package includes 2pcs 3.5" chain links. We stock other Stainless Steel Carabiners ranging in size from M3.5 to M12. Please contact us if you have any questions. We will be glad to assist you. E. WEIGHT: Our heavy-duty carabiner has a weight-bearing capacity of up to 2000 LBS, ensuring a relatively high level of stability and strength, providing a quick connection to meet various tough needs (NOTE: Not for mountaineering, rock climbing, ice climbing and high-altitude games).