Made of aluminum alloy. Features: Lightweight, waterproof, wear-resistant, high-strength, and durable D-shaped aluminum alloy with a polished finish. Can be attached to backpacks, key rings, water bottles, and anything else you need, with a secure lock. Great for outdoor activities such as connecting tents and ropes, camping, hiking, fishing, and trekking! Unopened, please refer to the second photo for dimensions, etc. For safety reasons, this product cannot be used for climbing, rock climbing, etc. Size: 8 x 4.5 cm Material: Aluminum Weight Capacity: 2kg - Type: Locking Carabiner - Type: Locking Carabiner Thank you for viewing.