For applications that require an Industrial Strength Tower Chassis, Arista offers the MPC 6070. This chassis is custom designed to provide maximum expandability and reliability. Unique to this tower chassis design is the dual locakable/swappable HDD bays and floor mount flanges. This allows the unit, and the data it contains, to remain in-place and secure. + MPC 6070A INDUSTRIAL TOWER COMPUTER = 3.0GHz Intel P4 = up to 2GB DDR 400 = 2x Locakable/Swappable HDD Bays = 6x Full Size PCI Slots = 2x RS-232, 2x RS-232/422/485 = 4x USB 2.0 ports = Dual Gigabit Ethernet + MPC 6070D INDUSTRIAL TOWER COMPUTER = 3.0GHz Intel Core2 DUO = up to 4GB DDR 400 = 2x Locakable/Swappable HDD Bays = 6x Full Size PCI Slots = 2x RS-232, 1x RS-232/422/485 = 4x USB 2.0 ports = Dual Gigabit Ethernet