A safety hook is an item used in conjunction with a safety rope

Carabiner, also known as "main lock", is the most commonly used connection tool for connecting ropes, flat belts, anchors, equipment, and other components. The safety hook and loop must be equipped with a locking function. The locking function is divided into two categories: manual lock and automatic lock. Hand lock is suitable for most environments, but it must be locked immediately after connection, otherwise accidents may occur due to accidental collision of equipment during operation. An unlocked hook and loop is like a gate in an open state, with its tensile force (breaking load) much lower than the locked state. There are two types: ordinary type (rotary type) and spring hook (self-locking type). The appearance is often like a "D" (rescue, military) or an "8" shape (engineering, architecture).