NEC Express 5800/230Eh - Manual (Page 215)

Upgrading Your Server 9-9
4. Remove the front mask to the right to release the tabs on the front mask from the chassis.
Installation
The front mask can be installed in the reverse order of the removal. Insert the four tabs at the right
end of the front mask into the holes on the front of the server, push the left end of the front mask to
the server, and lock the mask with the release tabs.