The most common manual initiating device is the fire alarm box, which many people refer to as a manual pull station.

A building fire alarm system uses a combination of automatic and manual initiating devices designed to signal the need for the building occupants
Manual fire alarm pull station can be single or double-action devices.
A single-action device requires the user to do only one thing, which most often is to pull the handle down.
A double-action device requires the user to perform two actions before the device is activated. which reduce unwanted alarms
also Protective covers can also be used to reduce unwanted activations of fire alarm boxes.

Manual fire alarm pull station should be in red color.
Manual fire alarm boxes are required to be located near the entrance of each exit. On each floor. of a building. the maximum travel distance to a manual fire alarm box is 200 ft.

The location requirement is that the manual fire alarm box must be within 5 ft of the exit door and mounted so that the operable part of the box is not less than 42 in. and not more than 48 in. from the floor. While not a code requirement. it is good practice to locate the manual fire alarm box on the latch side of the door. This ensures an open door will not block the manual fire alarm box from view.
Where a building. fire or life safety code requires a fire alarm system. most often they will require the installation of manual fire alarm boxes. NFPA 72 does recognize that some situations may have the need to initiate an alarm for some kind of emergency other than a fire.
Very good explanation !!! being an electrical engineer. It is very informative , gr8 work guys !!!