نظرة عامة7 lever lock is a type of mechanical lock that uses 7 levers to secure the lock mechanism The levers act as obstacles that must be correctly aligned in order for the lock to open Double locking refers to a locking mechanism in which a lock has two locking points that must be engaged in order for the lock to be secure This is typically used in high security situations such as in safes or vaults as it makes the lock more difficult to pick or force open A long shackle is a type of padlock shackle that has a longer shackle length compared to a standard shackle The shackle is the Ushaped piece of metal that goes through the loop or eye of the hasp or other locking mechanism to secure it in place Extra long shackle locks are commonly used in industrial and commercial settings as well as for outdoor applications such as securing bicycles motorcycles or boats They are available in a variety of materials such as brass steel or laminated steel and can be keyed or combinationbased