The Power Bar is only mentioned by a couple short sentences and a picture in the m998's documentation. As you can probably guess, it's a cable management system that is designed to reduce clutter. It more or less acts like a power strip only it's inside the PC. On the very top (upper left) edge of the Power Bar there are two Molex connectors and two 6-pin PCI-Express plugs that will get powered from the power supply. 

     Step 7 on the instruction pamphlet shows a Molex getting plugged into one of the top connectors. From there it looks like you'll just need to use deductive reasoning to figure out that another Molex and your PCI-Express power plugs should go there too.  Once that's done, the two PCI Express and four Molex connectors on the bottom of the Power Bar will be hot provided the system is on of course. From there, you'll use a variety of adapters (included with the m998) to connect your accessories and peripherals. I can't find anything that rates the Power Bar's maximum current carrying capacity. I only mention this because overloading it could bring a quick and nasty end to a PC, or an entire house if you're really unlucky.

    The thing about doors, you either like them or you don't. At least this one is only covering the front panel expansion ports. So even when its closed, you can still get to the power and reset buttons as well as see your LEDs.