PETZL CARABINER WILLIAM SCREW-LOCK is the perfect carabiner for belay stations. The WILLIAM asymmetrical large-capacity aluminum carabiner has a pear shape that is practical for easily connecting multiple items. The ergonomic shape and Keylock system make it easy to handle, even when wearing gloves. The WILLIAM carabiner is available in two locking systems: manual SCREW-LOCK or automatic BALL-LOCK, and TRIACK-LOCK.