Quickly and easily share a usb 20 device between up to four different computers the usb421hs 4 to 1 usb switch box allows for a usb 20 device to be shared with up to 4 different computer systems without having to disconnect and reconnect the cabling every time push button controls makes switching between computers quick and easy with additional keyboard hot key switching and windows based software also available with no external power adapter required and with its compact design the