Locks are mainly used for doors, cupboards, briefcases to store some precious items for safety and security purposes. In earlier days the locks are provided with the keys in which if the keys are lost then the lock cannot be opened, but nowadays there are different types of locks provided.
For these types of problems, retrofit locks are the best and smart choices. There are many models in locks. A combination of four digits, a combination of three digits, and a combination of three or four digits along with a major key are used with a keyword key to unlock. In older times, along with the main key, some rotating locks are present, in which those rotating locks have to be unlocked first, and then the master key should be used.
These code-based retrofit locks can be fitted inside the door and hide so that it cannot be opened with force and can be unlocked only by feeding the correct passcode. It is provided with a master key which can be used in case of any malfunction of the lock occurs. Nowadays the advanced methods of locking are also used such as using a smartphone application in which the specific lock can be unlocked by accessing the phone or typing a passcode in it. And another method is also there that knocks the screen of the phone called as Open Sesame process. It requires special programs for various platforms and the power supply for the locks are given by the lithium batteries.