What's the name of the hotel door lock?

What is the function of security door chain?

1. In the construction industry or lock industry, the security door chain, also known as security chain or security chain, is a metal chain with a lock installed inside the gate. It consists of two parts: sliding chain and chain buckle.

Second, the chain buckle is installed on the back of the door not far from the door edge. One end of the sliding chain is fixed on the door frame, and the other end is movable and can be inserted into the chain buckle behind the door for locking. When hanging the anti-theft chain, the door can only be opened to about 5 ~ 8 cm, so that people can't get through it and their hands can't reach the chain buckle behind the door, ensuring that when the owner opens the door to confirm the identity of the visitor, he will not be suddenly attacked by the other party. Because the sliding chain is easy to be cut by tools such as metal cutting pliers, the security door chain is rarely used as a door lock alone, but only as an auxiliary tool for theft prevention. Therefore, the sliding chain and sliding buckle security door chain is also called "intentional lock", which is intended to remind people to be more careful just in case. In addition, there is a kind of "safety door buckle" which uses metal rod instead of metal chain, which is also designed and used for the same reason.