664918-B21: HPE 1U Security Bezel Kit

The HPE QuickSpecs for the ProLiant DL360p Gen8 include 664918-B21, the 1U Security Bezel Kit.

HPE lists it under security options for this server.

664918-B21 specifications: Type Security bezel; form factor 1U; part of the HPE ProLiant DL360p Gen8 product line.