A door closer is a type of standard hardware designed to close a door either mechanically or automatically. It’s usually mounted on the top of doors or on the door frame. Then an arm connecting the door, the door closer, and the shoe, which is the receiving end of the mechanism. They are often installed on and required for stairway doors as a means to contain the spread of fire and smoke, while also protecting emergency exit routes.

In addition to the performance of the closer in situations of a fire, the other criteria might include control over the closing rate, resistance to opening forces, durability, and safety.