Its A USB 3.0 connector for the Usb 3.0 jack on front of your case , look for a blue Usb connector on your back panel & conect it in to it , this way you wont have to go around back for the USB 3.0 connection , from what i have read this is the way case manufacturers are doing it at the moment as there is no current avialability on internal MOBO conections for USB 3.0 ( but these posts i have read could be older posts & not so relevent by now , maybe USB 3.0 is in fact available On internal MOBO by now , couldnt really say)