The Cisco UCSX-9508-RBLK is an Active Cooling Module (also referred to as a rear blank or filler) specifically designed for the Fabric Expander Module (FEM) slot in the Cisco UCS 9508 Modular System Chassis. It helps maintain proper airflow, ensures thermal efficiency, and supports chassis-level cooling balance when a FEM is not installed. This module is critical to the thermal management system of the UCS 9508 chassis.
eBay