2U 12-Bay Trayless Storage Server Rackmount Chassis, Suport PS2 ATX Power supply, support 600mm cabinet space, the chassis not only have a compact size, but the trayless and hot-swappable 3.5" bays make this chassis a new breed of storage servers. The three mini-sas backplane connerctor provide more stable data transfer, and support Mini-sas or SATA Mother board.