A D-shackle, also known as a chain shackle or dee shackle, is a type of fastening device used in rigging and lifting applications. It consists of a curved metal loop shaped like the letter "D," with a pin or bolt closure across the straight side of the loop. D-shackles are commonly used to connect chains, ropes, or cables to lifting or pulling equipment, providing a secure attachment point. They come in various sizes and load capacities to suit different lifting and rigging needs, making them essential tools in industries such as construction, maritime, and manufacturing.