4U Compact Stylish Rackmount Chassis 6 x 3.5" Hotswap Drives PS2 PSU - Supports Front Access USB2.0 x2 - Power and HDD LED - Power and Reset Switch - Support ATX PS2 Power Supply D-416-B6SA is a reliable and stable 4U-high server chassis. The full size I/O supports all ATX motherboard with a Dual-core/ Quad-Core processors and the backplane supports 7 full-height add-on cards. This chassis is 21" deep and has optional three 80mm cooling fans in the center and two 60mm fans at rear for air ventilation. In addition, D-416-B6SA supports a standard ATX PS2 power supply to meet regular server system applications.