Remove the two supplied thumbscrews and slide the case's top rearward to open the case. The top is held very tightly and there is no provision for holding the top, such as a lip on the rear of the panel, so removing the top is pretty difficult. It should loosen up after being removed a number of times.
The nMediaPC 6000B supports both ATX and mATX/uATX motherboards. There are seven full expansion slots, and the design of the case should allow most video cards, though full sized cards (10.5-11) with PCI-E power connectors on the rear of the card rather than the side will surely be a very tight fit, if they will fit at all without modding the case. All of my large video cards have rear connectors so I won't be able to try.
The height of the case from motherboard tray to top panel is just a hair over 6. Keep in mind that a typical 120mm tower cooler is about 6 tall so your choice of CPU cooler will be limited to (gasp!) stock style coolers, those configured with the radiator parallel to the motherboard, and 90mm-92mm tower coolers. This is an HTPC case, and generally not intended for gamers and overclockers. I will be using a very low profile deck styled CPU cooler and a 9600GT video card. I've been using a 9800GTX+ card on this rig and will take this opportunity to break out something that doesn't use quite as much power. This is the rig I mentioned earlier that is used for watching and recording TV - it is never used for gaming or overclocking.
The case has a unique shelf for mounting the drives. It will hold one 5.25 optical drive and up to six 3.5 hard drives.
The drives mounted on the upper shelf, including the optical drive, will be attached by installing screws on the BOTTOM of the drives. If using all six hard drive bays, the upper two drives must be installed before the lower ones so the screw holes won't be covered up.
Though the electronics are exposed, they will be covered by the shelf so there is no danger of something touching them. There is a 120mm intake fan included, and a place to put a second 120mm fan but it isn't included.
There is a pair of 80mm fans on the rear of the case for exhaust. As they each have a 4-pin Molex connector, let's hope that they are truly designed to be quiet.
The case feet go along with the stereo component theme. They appear well made, a good thing as I have had some really flimsy ones in the past. They are attached by screws.
Included with the case are screws, zip ties, ball ties, and some extra HDD grommets.