I was looking for a switch to work on two different computers on one 4K monitor. The first one I bought worked fairly well but wasn't very high quality in terms of finish. However, I didn't need some super high. That was the perfect middle ground for me.
TESmart 1080P 60Hz USB VGA KVM Extender Over Cat5e Cat6 Ethernet Cable - Long Range 984ft/300m (Sender+Receiver)
10 Review
4 Port USB 3.0 Switch Selector - Pubioh KVM Switch for Mouse, Keyboard, Printer, Scanner - 2 in 4 Out Sharing Box with Switch Button and 2 USB 3.0 A to A Cables
11 Review
π TRENDnet TK-803R: 8-Port Rack Mount KVM Switch with VGA & USB Connection, USB/PS2 Support, Device Monitoring, Auto Scan - Control 8 Computers/Servers
10 Review
CKL Quad Monitor HDMI KVM Switch 4 Port 4K@30Hz with Cables - Extended and Mirrored Display Support for Windows, Linux, and Mac
11 Review