IP FHD Digital KVM Extender over Fiber/Cat5--Dual HDMI / USB2.0 / Audi
AV Access 4K HDMI Extender, 2-Way IR, PoE & RS232
USB to RS232 Adapter with PL2303 Chipset, CableCreation 6.6 ft USB 2.0 Male to RS232 Female DB9 Serial Converter Cable for Cashier Register, Modem, Scanner, Digital Cameras, CNC,Black - Walmart.com
Amazon.com: KVM Switch with Serial Port Control, 4K@60Hz 4 in 1 Out HDMI KVM Switcher Box for Share Mouse Keyboard and Monitor, Can Work with Pi-kvm, Compatible with Windows/Linux/Mac System : Electronics
HDMI/RS232 100m Extender Kit, HDBT, 4K/60 – Muxlab Dealer Portal