Tripp Lite's NetController 4-Port, 1U rackmount KVM Switch is an affordable, highly-flexible enterprise class KVM Switch, which allows the user to connect either USB or PS/2 keyboards and mice. In addition, P780-Series USB/PS2 combo KVM cable kits allow you to connect either USB or PS/2 computers, without the need to purchase separate cables or adapters. Control up to 4 directly connected computers, or expand the number of connected computers to up to 244 by daisychaining up to 15 additional B042-Series KVM switches. Switch between connected computers via the On-Screen Display (OSD), pushbuttons, or keyboard hotkey commands. Other features include: password protection, auto-scanning, auto-logout, firmware upgrade and video support up to 2048 x 1536 (QXGA). Mounts easily in a standard 19" rack/cabinet and includes all necessary mounting hardware. Compatible with all major operating systems. Constructed of heavy-duty steel housing. 3 year limited warranty.