Port replicator external interfaces serial port parallel ps2 x2 usb 20 usb 30 lan rj45 audio out audio in video outputs vga displayport 2x dvi 2x usb 20 ports 1 usb 30 ports 1 compatible with dell precision m4500 dell precision m4600 dell precision m4700 dell precision m4400 dell precision m2400 dell precision m4300 dell precision m2300