Used Avocent SwitchView 4 port KVM with 4 sets of cables. This is a model that uses the old PS/2 style round keyboard and mouse cables (not USB!). I have two of them I have removed from my lab. You are bidding on only one. I used them both without a power supply. They have a 6v 0.7A plug in the back. I don't believe that they came with a power supply, and never needed one for them to function. (nopower supply is included)