Review on Rybozen KVM Switch HDMI 2 Port Box with USB and HDMI, Share Keyboard Mouse Printer and HD Monitor, Support 4K HUD (3840x2160), includes 2 HDMI and 2 USB Cables by Ikki Martini

It worked great for the first five minutes I was online. Quick and easy switching between HDMI sources. But the USB ports are terrible and after five minutes it was terrible. They seem to keep losing contact with my computers. When typing on the keyboard, it skips random letters or behaves as if a key is held down. Using my mouse results in jerky movements and missed clicks and double clicks. It doesn't even recognize my webcam. I've checked my peripherals plugged directly into my computers and they're working fine, so there's something wrong with the switch. Seemed too good for the price and apparently it was!