Three HDDs can be installed in each cage and there are large enough gaps between them. They should be cooled properly.
The HDDs are secured with two long screws on each side of the cage. Don’t lose the screws – it won’t be easy to find a replacement for them.
If you want to limit yourself to three (or fewer) HDDs, you can install them all into the bottom cage. Then you can attach a plastic carcass for the installation of an additional 120mm fan to the top of the top cage. This fan will be driving the air along the graphics card, cooling the latter. This opportunity may be useful for systems with two graphics cards.
The developer didn’t forget about floppy drives and card-readers. You can install them using plastic rails and a special bracket for a 5-inch bay. It is good that the bracket is meshed like the others and won’t become a conspicuous element of the front panel.
If you’ve got a very long graphics card, you can fasten the included plastic piece to the front rack and use it as a support for the back of the card. That’s a nice trifle, but not quite properly designed. The piece is only one, so it cannot be used for configurations with two graphics cards. And the graphics card must be a specific size for you to use this thing. My card proved to be insufficiently long, for example.
The mainboard and expansion cards are secured with screws. You should first install the PSU, though. If you’ve got a PSU with a 120mm fan, you should position it with the fan facing upward. Note that the PSU must have long cables – they have to reach through the entire case almost.
I wish the case were a couple of centimeters longer for more comfort. There is just too little room for cables between the back part of long expansion cards and the HDDs. It is hard to lay the cables there normally.
I would like to show you a photo of the operating system case. Its fans are highlighted and look very beautiful.