"Batteries not Required to OperateTripp 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. - NetController 4-Port, 1U rackmount KVM switch - Control 4 computers via a single VGA monitor and USB or PS/2 keyboard/mouse - Control up to 244 computers by daisychaining up to 15 additional B042-Series KVM switches - P780-Series USB/PS2 combo KVM cables kits allow you to connect either USB or PS/2 computers, without the need to purchase separate cables or adapters - Compatible with all major operating systems- B042-004 NetController 4-Port, 1U rackmount KVM switch - External Power Supply with NEMA 1-15P Plug (Input: 100-240V, 50/60Hz, 0.3A / Output: 9V, 1A) - Rackmount hardware - 20.32 cm (8-in.) Daisychain cable ( for longer daisy-chain cables, see Tripp Lite P781 series cables) - Daisychain terminator - 1.22 m (4-ft.) HD15 to DB9 firmware upgrade cable - CD with owner's manual and quick start guide - Quick start guide - NetController 4-Port, 1U rackmount KVM switch - Control 4 computers via a single VGA monitor and USB or PS/2 keyboard/mouse - 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 244 computers by daisychaining up to 15 additional B042-Series KVM switches - Allows for easy customization of ports by daisy-chaing any combination of B042-Series KVM's (4-, 8- or 16-port) - Standard 19"" Rackmount size - hardware included - On-Screen Display (OSD) menu for intuitive operation and easy control - Switch between connected computers via the On-Screen Display (OSD), pushbuttons, or keyboard hotkey commands - Supports video resolution up to 2048 x 1536 - Password protection and auto-logout features - Firmware upgradeable - Robust metal case design ensures best EMI/RFI shielding and video quality - Hot-swappable: disconnect and reconnect USB computers without rebooting - Supports standard 5-button Microsoft, Logitech, or comparable mice - Supports standard Microsoft, Logitech, or comparable keyboards - Compatible with all major operating systems - Constructed of heavy-duty steel housing"