Rails includedDual Power2 heatsinks includedBarebones Chassis only no Memory no CPUCan fit up to (front and back) 36 x 3.5" HDD/SSD'sSystemboard Specifications:Dual Socket comptiable with Intel® Xeon® processor E5-2600 v3, Intel® Xeon® processor E5-2600 v4.Up to 3TB† ECC 3DS LRDIMM, up toDDR4- 2400†MHz ; 24x DIMM slots2 PCI-E 3.0 x16, 3 PCI-E 3.0 x8, and 1 PCI-E 2.0 x4 (in x8) slotQuad LAN w/ Intel® X540 10GBase-T10 SATA3 (6Gbps); RAID 0, 1, 5, 10Integrated IPMI 2.0 and KVM with Dedicated LAN5 USB 3.0 (2 rear, 2 front panel, 1 Type-A) 4 USB 2.0 (2 rear, 2 front panel)