2. Card opening: After the door lock is locked, hard cards such as membership cards and bank cards can be directly inserted into the door lock and pushed hard.
Keys are people's daily necessities. With the passage of time, the daily necessities of the past have evolved into today's collections. Keys, mainly made of copper and other metals, can be described as varied and can be roughly divided into the following categories: ring keys: ancient Romans wore robes, which were not allowed to be used as pockets according to the custom at that time. In order to prevent the key from being lost when going out, a ring key was made and worn on the finger like a ring after going out, which is both safe and beautiful.