Climbing buckle (/ k? r ?? bi？ n？ R /) is a special shackle, a metal ring with a spring-loaded door, which is used to quickly and reversibly connect components, especially in systems with strict safety requirements. The word is an acronym for karabinerhaken, a German phrase used by karbin riflemen or climbers to attach objects to belts or bullet belts.

Over the past decades, mountaineering buckle has been improved several times to make it more light, reliable and durable

Mountaineering buckle, usually called D-ring by military professionals, is widely used in rope intensive activities, such as mountaineering, tree cultivation, cave exploration, navigation, hot air balloon, rope rescue, construction, industrial rope operation, window cleaning, torrent rescue and acrobatic performance. They are mainly made of steel and aluminum. Those used in sports tend to be lighter than those used in commercial applications and rope rescue. Mountaineering key rings, commonly known as mountaineering clasps or small lockers, and other light clips of similar style and design have also become popular. Due to the general lack of load testing and safety standards in the manufacturing process, most products are marked with "no climbing" or similar warnings. From a etymological point of view, technically, any metal connection to a spring door is a mountaineering buckle, but the strict usage in the climbing community only refers to the load-bearing equipment that is manufactured and tested for safety critical systems such as climbing and mountain climbing.

Attach the envelope to the shopping basket using the safety buckle on the balloon with a rated capacity of 2.5 tons, 3 tons or 4 tons.

The load-bearing screw lock type safety buckle is used to connect the diver's umbilical cord to the diver's safety belt provided by the surface. They are usually rated for a safe working load of 5 kn or more (equivalent to a weight of more than 500 kg).