5"1/4 Bay with Silver aluminium which couples to a rear PCI bracket with D shaped connector.
Externally, this has a cable that interfaces with the bracket, to rear IO ports, extending them to the front panel of a case, or up on to a desktop.
Features USB 2.0 x 2, Audio In, Out, Mic, Game Port, 1394 Firewire and PS/2 Mouse
These are all external connectors for rear of a motherboard, they don't connect to Internal USB headers.
New systems won't support old connections like Game Port / Firewire but of course it can be used partially for the available connectors if required.
Retro item we found a supply of in our stock room - still new and boxed, but priced low to move them.