Control four computers using one monitor, PS2 keyboard, and PS2 mouse with Ultra U12-40716 GammaView 4005 4-Port PS2 KVM Switch. The Ultra U12-40716 GammaView 4005 4-Port PS2 KVM Switch allows users to effortlessly control four systems without having to buy additional computer peripherals. It is ideal for the home office where business files are kept on one computer and personal files on another. The Ultra U12-40716 GammaView 4005 4-Port PS2 KVM Switch features all-in-one compact design and built-in 5.9ft cables.