Servers might be shipped with replacement fillers for hard drives and PCI cards. A filler is an empty metal or plastic enclosure that does not contain any functioning system hardware or cable connectors.
The fillers are installed at the factory and must remain in the server until you replace them with a functional component to ensure proper airflow through the system. If you remove a filler and continue to operate your server with an empty slot, the server might overheat due to improper airflow. For instructions on removing or installing a filler for a server component, refer to the topic in this document about servicing that component.