The 400R has been carefully designed for upgradability. With USB 3.0, support for 2.5" SSDs right out of the box, eight expansion slots, up to 316mm of room for GPUs, and even room for a full 240mm radiator, the 400R packs a serious punch. And if cooling is your concern, the 400R has ten fan mounting points for cooling flexibility. Three 120mm fans - two in the front, and one in the rear - are included, so you"re ready to start building right away. The side panels are easy access, with two captive thumbscrews on the rear of each so you never lose them.