custom sound volumn knob 1. cnc machining 2. fabrication service ... per customers' requirements, in perfect condition.3.Send the parts by express, 3~5 days door to door service.Application ... , MP3, MP4, earphone, hearing aids, surgical instrument etc..RemarksAll parts are not in stock, customization only!Any RFQ, please feel ... .We are looking forward to our Win-Win Cooperations!! custom sound volumn knob