What is the name of the lock installed on this fire door?

This kind of door lock is called fireproof door lock, also called fireproof hand lock. Mainly used for fire doors, it can be divided into two categories. 1 is a common fire lock, which is mainly used for locking and opening fire doors, and the other category 1 is a special fire lock (commonly known as fire escape lock), which is mainly used for emergency escape to ensure personnel safety.