D-Link 4-Port USB KVM Switch (DKVM-4U) the d-link 4-port usb kvm switch (dkvm-4u) allows you to control up to 4 pcs using one monitor, usb keyboard and usb mouse. it is ideal for anyone who has to work with more than one computer to eliminate the need for additional monitors, keyboards and mice, saving the money and freeing up the desktop space.