Features: 1. Double Ended Swivel Ring is made of 304 stainless steel, which is hard and durable, does not rust, and is resistant to corrosion, and buckles of common metal. 2. Industrial-grade swivel designed. Hot forged with large bearings and heat-treated, stainless steel axles. 3. Designed for applications where a quick swivel assembly with a hook or quick link is expected. Usually used for chains, ropes, etc. to prevent knotting after rotation. 4. Great for backpack, keyring, camping, hiking, walking, travel, fishing, indoor or outdoor equipment or gear or tools carabiner. 5. M4, M5, M6 are optional, to meet your different needs. Specification: Material: 304 Stainless Steel Product Color: Silver Product Size: 5 x 2 x 1cm, 7 x 2 x 1cm Product Weight: 19g, 30g, 50g Optional: M4, M5, M6 Package Included: 1 x 304 Stainless Steel Swivel Ring