The b004-dua4-hr-k is a 4-port DVI/USB KVM switch with audio and USB 2.0 Peripheral sharing. It allows you to access, control, boot and reboot four computers from a single USB keyboard, USB mouse, and monitor. Switching between connected computers is quick and simple using keyboard hotkeys or pushbuttons. An independent audio/mic and USB peripheral switching function allows for an uninterrupted experience. A computer can be printing on a printer connected to one of the USB 2.0 Peripheral ports, while you listen to audio from and access another computer; all at the same time. The b004-dua2-hr-k uses DVI-I technology, allowing for the transmission of a digital (up to 1920 x 1200) or analog (up to 2048 x 1536) signal. A dvi to VGA adapter, such as Tripp Lite's p126-000, is required for conversion to an analog monitor. Whichever you use, full time DDC support provides the necessary EDID information required for optimal video performance on windows 7 and other operating systems. Compatible with all major operating systems. 1-Year limited warranty. Key features 4-port dvi dual Link/USB KVM switch with 7.1 Channel surround-sound audio and USB 2.0 Peripheral sharing (b004-dua4-hr-k) built-in 2-port USB 2.0 Hub allows USB devices to be shared amongst computers connected to the KVM switch 3.5mm Mini stereo speaker and microphone jacks allow a single microphone to provide audio input to each of the connected computers, and let you listen to the audio output of each computer on a single set of speakers b004-dua4-hr-k features additional audio jacks for use with 2.1 Channel surround-sound an additional set of console audio jacks are conveniently located on the front panel of the KVM switch, making them ideal for use with IP phones the KVM, USB and audio can be switched independently of each other.