Add four external usb 3 0 ports to your notebook or ultrabook with a slim portable hub compatible with hp pro book 4540s lenovo carbon x1 portable 4 port usb 3 0 hub compact usb 3 0 hub with cable usb 3 hub w attached cable mobile usb travel hub notebook laptop usb 3 0 hub ideal for ultrabook and mac book users with limited usb 3 0 ports perfect laptop accessory adding usb 3 0 ports connect peripherals and multiple external hard drives in the home or office built in cable