2U, ATX 12" x 10", E-ATX 12" x 13", EE-ATX 13" x 13.68". Support up to ATX 12"x13" MB with rear 2.5" HDD option installed, 24 x 2.5" hot-swap SAS/SATA drive bay, optional 2 x 2.5" hot-swap drive bay, 24-port 2U SAS3 12Gbps single-expander backplane, support up to 20x 2.5-inch SAS3/SATA3 HDD/SSD and 4x NVMe/SAS3/SATA3 storage devices, 1U 1200W/1000W Titanium Power Supply W/PMbus W76xL336xH40mm, 7 low-profile expansion slot(s), 3 x 8cm high-performance PWM fan(s), Optional 5 x 6cm 4pin high perfor