Buyer beware - it may need a power supply
I bought this so that I can easily switch between my home computer and work laptop when working at home. Unfortunately if only my home computer is connected it will not display anything. Works OK if the HDMI output from my work computer is also plugged in. It seems as if the unit needs the power input from both of my computers to function at all, so if I have my work laptop at work nobody can use the home computer without plugging its HDMI output directly into the monitor, which kind of defeats the purpose of the device. So I would not recommend this device unless you can try it in your setup first.