Carabiners, often called D-Rings by military professionals, are widely used in rope-intensive activities such as climbing, arboriculture, caving, sailing, hot air ballooning, rope rescue, construction, industrial rope work, window cleaning, whitewater rescue, and acrobatics. They are predominantly made from both steel and aluminium. Those used in sports tend to be of a lighter weight than those used in commercial applications and rope rescue. Often referred to as carabiner-style or as mini-biners, carabiner keyrings and other light-use clips of similar style and design have also become popular.
