Supports ATX (PS2) / 2U single / 2U redundant power supplies Supports 1 x 2.5' SSD and up to 2 x 3.5' HDD^^5Gbps USB 3.1 Gen1 interface (downward compatible with USB 2.0 & USB 1.1) Dual 5.25' expansion bay brings flexibility in installing 5.25' devices Built-in fan bracket supports up to two 80mm x 25mm fans Supports Micro-ATX motherboard (9.6' x 9.6')^^Supports 4 low-profile PCI / PCIe slots