ATEN 4-port USB Boundless KM Switch - 4 Computer(s) - 1 Local User(s) - 1 x Network (RJ-45) - 8 x USB - Rack-mountable - CS724KM

Single USB keyboard and mouse control up to 4 computers
Daisy-chain two CS724KM units to control up to 8 computers with a single keyboard and mouse
Boundless Switching - simply move the mouse cursor across the display border and onto the corresponding display of the target computer to switch the keyboard/mouse operations from one computer to the next.
Boundless Switching Configuration Utility - an intuitive GUI tool that enables users to customize monitor layouts
Port selection via front panel pushbutton, keyboard hotkey, mouse cursor, mouse wheel, and RS-232 commands
Independently switch keyboard/ mouse, USB peripheral, and audio focus via hotkeys
Supports RS-232 serial commands
Supports Windows operating systems
No software required
Bus-powered - no external power adapter required