The carabiner, also known as the "main lock", is the most commonly used connection tool for connecting ropes, slings, anchor points, equipment, etc. The safety shackle needs to have a locking function. The locking function is divided into two categories: manual lock and automatic lock. The hand-turn lock is suitable for use in most environments, but it must be locked immediately after connection, otherwise the lock door may be opened accidentally due to accidental equipment collision during operation. An unlocked shackle, like a gate open, has a much lower pulling force (breaking load) than a locked state. There are two types: ordinary type (rotary type) and snap hook (self-locking type). Shapes such as "D" (rescue, military), "8" (engineering, construction).
The process flow for using snap hooks typically involves selecting the appropriate size and type of snap hook for the application; attaching the snap hook to the rope or cable; attaching the other end of the rope or cable to the anchor point or accessory; and using the spring-loaded gate to quickly and easily connect or disconnect the two items.