Which part of a fire extinguisher contains the extinguishing agent?

The cylinder of a fire extinguisher is where the extinguishing agent is stored under pressure. This part is typically made of metal and is designed to withstand the pressure of the agent, whether it be water, foam, powder, or carbon dioxide. When the extinguisher is discharged, the pressure in the cylinder forces the extinguishing agent out of the nozzle, allowing it to be directed at the fire. The cylinder is critical to the functionality of the extinguisher, as without it, there would be no means to contain or deliver the extinguishing agent effectively. The other components, such as the nozzle, hose, and gauge, serve different purposes, like directing the flow or indicating pressure levels, but they do not hold the extinguishing agent itself.