Which through penetration system represents a wall being penetrated?

In the context of through penetration systems, particularly concerning walls, the correct choice indicates a specific type that is used to mark wall penetrations. The classification system typically follows a format that includes the prefix 'W' for walls, followed by a unique identifier number that designates different testing or material properties associated with that specific system.

The combination in the correct answer signifies compliance with safety standards and the specific characteristics required for a through penetration system that has been tested for fire resistance and other safety metrics in wall applications. By focusing on this designation, one can quickly identify that the system has undergone proper testing in a wall context, ensuring that it meets the necessary requirements for both safety and performance in fire-rated walls.

Meanwhile, the other options share the same format but are associated with different attributes or are designated for different applications, which may not exclusively pertain to wall penetrations. Understanding these classifications is crucial for ensuring compliance with safety regulations and proper installation practices in electrical and construction projects.