. The SV431TDVIUA 4-Port Triple Monitor DVI USB (Universal Serial Bus) KVM Switch allows 4 PCs (each with 3 DVI video outputs) to share monitors 1 microphone & set of speakers 1 keyboard & 1 mouse as well as an additional USB (Universal Serial Bus) 2.0 peripheral such as an external hard drive thumb drive printer or webcam.. The Triple DVI KVM switch enables you to switch back & forth between 4 multi DVI PCs at the touch of a button while maintaining professional-level video quality on all monitors at resolutions up to 1920x 1200. The triple DVI KVM switch also features an integrated USB (Universal Serial Bus) hub port which allows USB (Universal Serial Bus) 2.0 peripherals to be shared between attached systems eliminating duplicate peripheral costs & offering the convenience of sharing stored data between PCs. The SV431TDVIUA 4-Port Triple Monitor DVI KVM Switch is backed by a Star Tech.com 3-year warranty & free lifetime technical support.PLEASE NOTE While both DVI-I (analog mode) & DVI-D (digital only) are supported by the KVM both source PCs must output the same signal type for proper switching. It is recommended wherever possible to use DVI-D cables across all PC to KVM & KVM to Console connections. If necessary please contact our technical support team for assistance identifying your source..