Summary: You will need to find and purchase cable kits for each of the 4 channels in this switch, either either USB or PS/2 depending upon your use. It does come with a cable for the master port, so no worries their. This device greatly simplifies the desktop when multiple computers are to be used. I have a screen for each, so am simply switch the keyboard and mouse, thus the video cables hang free. Works great, no problems.
Summary: It turns out that this doesn't work like normal KVM switches: it uses special non-standard adapter cables, which apparently aren't necessarily available on amazon.com, or if they are cost a lot. So you can't replace your existing 2-port KVM with this one, for example, and reuse the existing cables. And you may not even be able to use THIS KVM because you may not be able to find the cables you need.
Summary: There is plenty to like. First off it works well, and isn't that the main thing. One of the things I like the best is that it is able to power itself from the cables connected to the PCs and KVM so there is one less 'wall wart' to try and find a place to plug in. The 'combined cables' are a mixed blessing. From a neatness and reliability standpoint they are great. But that makes them proprietary, so you need to buy all new cables for this ...
Summary: I would agree with the cable shortcomings mentioned by the other reviewers (proprietary, expensive, and not included), and add that Tripp-Lite already offers another better model that does not have this drawback: Tripp Lite B006-004-R 4-Port USB KVM Switch. Uses standard USB KVM cables.
Summary: As others have said, you cannot use any other cable. I attempted to use some cables we use for our servers that are of high quality. The video was fine, but would not take input from the Keyboard and mouse. Beware, you must buy their cables. This is a good device otherwise. Works very well. They really need to include cables when purchasing, at least some PS2 cables.