Used KVM Switch (first photos) HDMI USB 3.0 4 Ports 4K 60Hz 18Gbps 4 Computers with 1 Keyboard and 1 Mouse + Remote Control + an extra KVM switch for spare parts (last 2 photos).
Both switches come with an IR receiver for the remote controls, mounting brakets and chargers.
The extra KVM switch works but with faulty audio (if I'm not mistaken). However since I have no use for it at the moment, I'm adding it to the offer.