Norco 2U Rack Mount 1 x 5.25-Inch Drive Bay, 4 x 3.5-Inch Drive Bays Server Chassis RPC-240 2U rack mount design, meets EIARS-310C standard. 1 x 5.25" drive bay, 4 x 3.5" drive bays (maximum 5) Support Micro-ATX (9.6" X 9.6") motherboard and Mini-ITX (6.7" X 6.7") motherboard 2x80mm front ball bearing fans for better ventilation Front accessible USB port