The Rosewill TU-155 II 500 is full of features that make it a cinch to build in, and make your new system look good! There's plenty of room for expansion with six external drive bays (four 5.25" and two 3.5") and three internal 3.5" drive bays. 7 expansion slots on the back give room for add on cards, and mount your drives without pain with tool-less rails for optical drives. Recognizing that ventilation is a key component of system performance, Rosewill included plenty of ways to keep your system cool, including an 80mm fan and a dedicated duct for the CPU fan. Side vents by drive cage help all of the hard drives running cool in the hottest situations. There is a 500W power-supply delivers ample power for your needs and comes with connections for the most current applications including SATA and PCI-e. Build the system you need in the case that'll keep it happy and safe! With Power Supply: Yes Power Supply Mounted: Top With Side Panel Window: Yes External 5.25" Drive Bays: 4 External 3.5" Drive Bays: 2 Internal 3.5" Drive Bays: 3 Front Ports: USB, IEEE 1394, Audio - HD & AC97 plugs Side Air duct: Yes