A carabiner is a metal loop with a spring-loaded gate, commonly used in climbing, hiking, and other outdoor activities. It allows for quick and secure connections between ropes, harnesses, and gear. Carabiners come in various shapes and sizes, each designed for specific uses, such as locking carabiners for added security or non-locking carabiners for quick access. These versatile tools are typically made from aluminum or steel, providing strength and durability. Carabiners are essential for safety in activities like rock climbing and mountaineering, where they help manage equipment and ensure secure attachments to anchors or other gear.