I purchased the FatShark transformer to be used as a spectator set and monitor. Found it inconvenient that there was no great way to transport it without it being in the goggle casing, which is huge. Also didn't like that there was no connect the battery to it to pass to a friend.
This cover snaps onto the front of the monitor using the tripod mount and the slot at the top (where it mounts into the goggle casing) to protect the screen while transporting. It also snaps onto the back, and has slots where the battery mount can snap in. Finally, the battery is at a good height to use it as a kickstand to set the whole thing down at a good viewing angle.
Note: one drawback is that it covers your channel buttons and joystick for settings change, but since my main purpose was protection during travel, I was ok with this.