This is an ATEN 17" LCD KVM console drawer with an integrated 8-port PS/2-USB combo KVM switch — a slide-out rack unit that packs a 17" monitor, keyboard and touchpad into a single 1U-style tray so a data centre technician can manage up to eight servers from one screen instead of dedicating a monitor to each. The 'combo' switch accepts both legacy PS/2 and USB keyboard/mouse connections from the target servers, and an extra console port lets a second local KVM station or cascade switch be attached to extend reach beyond eight ports. The (US99KB/USKB/SPKB/OUTKB) suffix denotes the keyboard layout/language and power cord options this unit ships with, rather than a functional difference.