The Petzl William Screw-Lock Aluminum Carabiner is a HMS pear shape. It offers a large capacity and wide opening. This design is great for easily connecting multiple items. The fluid interior design limits the risk of having a catch point and facilitates rotation of the carabiner. It can be used with the CAPTIV bar to favor positioning of the carabiner along the major axis, to limit the risk of it flipping and to keep it integrated with the device. The manual screw-lock with red band provides a visual warning when the carabiner is unlocked