The M-140-ITX M series of trayless storage server rackmounts 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 chassis also has a built-in 250W flex power supply and four peer-to-peer SATA ports on the backplane to support the latest SAS and SATA hard drives. The M series chassis are also available in 2U, 3U, and 4U form factors.