The B004-DUA4-K-R is a compact 4-Port DVI/USB KVM Switch with optional audio and microphone switching function. It allows you to access, control, boot and reboot four, DVI- and USB-enabled multimedia computers from a single console (keyboard, monitor and mouse). The independent audio/mic switching function allows an uninterrupted audio experience - you can continue listening to audio even when you switch to the other computer. This KVM switch uses DVI technology for digital video signal transmission to reduce undesirable distortion from conventional analog/digital conversion. Both DVI Single Link digital video ( up to 1920x1200 ) and DVI analog video ( up to 2048x1536 ) are supported. It also includes innovative, easy-to-use KVM Switcher Software for Windows and Macintosh platforms. A small client application facilitates your KVM switching operations such as computer selection, hot key sequence programming, auto-scanning, auto-scan delay time programming, independent or simultaneous audio/computer switching and more. Compatible with all major operating systems. 1 year limited warranty.