An electronic device having a USB connector is provided comprising a partial outer sleeve reaching short of the USB connector and securely holding thereof and a shorter inner sleeve extending little over the USB connector and partially housed in the outer sleeve in a sliding relationship. The USB connector is connected to functional circuit on at least one printed circuit board. A short piece of adaptor bracket permits the selected printed circuit board fastened in a uniform profile to the containing space of the outer sleeve so that a determined size of outer sleeve may hold a variety of printed circuit boards in a constantly acceptable tolerance.