1. Tube body: The tube body is the primary component of the tube and contains both the vacuum connection port and the internal filaments. It also houses the external contact pins and the internal tap structures.
2. Filaments: The filaments are wound to form a circuit and are usually made from tungsten, titanium, or molybdenum alloys.
3. Vacuum connection port: This is the connection port to the vacuum, which is used to evacuate the tube.
4. Contact pins: The contact pins connect the tube to other circuits and can be made of various metals.
5. Internal tap structures: These are the structures inside the tube that are responsible for controlling the voltage and current. This is done by controlling the amount of current in each filament as well as the voltage levels.