Features The ADEK 291-B 2U rack mount computer case incorporates one 3.5″ and one 5.25″ bay with all switches and other controls protected by a locking door. The 6-slots provide exceptional expansion capability. The 291-B 2U rack mount chassis accepts standard PS/2 power supplies. The 291-B ships with the 6-slot butterfly backplane. Optional backplanes are available. These optional ball-bearing sliding rails are ideal for all mounting requirements. Rails are available in 18″, 22″ and 24″ sliding range capacities.Choose the size best suited for you. 2U chassis height Accepts full length single board computers Ships with 6-slot butterfly backplane with 4-PCI and 2-PICMG slots (optional backplanes available) Locking front door protects disk drives, power switch, USB ports, etc. Dual ball-bearing fans with filters keep things cool Air filter protects unit in industrial environments Supports PS/2 size power supplies External drive bays: 1 x 3.5", 1 x 5.25" Internal drive bay: 1 x 3.5" Dimensions: 18.9” W x 3.4" H x 17.1 D (Built for standard 1