HP D8520-63013 - Hot-swap fan assembly - Includes three fans - Mounts in the fan Tray in the center of the chassis assembly Retail
HP D8280-63000 - Duplexing backplane - Attaches to `hot swap` bay backplane to split 6 bay `hot swap` cage into two 3 bay units with separate connectors - Duplexing Backplane - Attaches to Hot Swap Bay Backplane to Split 6 Bay Hot Swap Cage into Two Retail
