This KVM switch is just what the doctor ordered. No more jumping from one laptop to another to type a message. I have my personal and work laptops connected at the same time, which use the same keyboard, mouse, monitor, printer and speaker (built into my monitor but could also be external speakers. You can also connect a microphone. It's very easy very well to set up, although the instructions don't specify which audio in/out is which (green is audio out). The hub port can be for any other external device you want to share, in my case it's a printer/scanner. I highly recommend this product.
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 HDMI 2.0 4 Port KVM Switch with 4K@60Hz, 2K@144Hz,1080P@120Hz Support, 18Gbps Bandwidth, USB 2.0 Keyboard/Mouse/Printer/Monitor/PC Selector, Audio Out/Mic In, HDR10, Dolby Vision, Dolby/DTS, HDCP2.2 Compatibility
10 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