custom sound volumn knob 1. cnc machining 2. fabrication service 3. tolerance +-0.01mm 4. ISO9001 manufacturer Product TypePrecison Audio PartsMaterialStainless steel, Carbon ... by express, 3~5 days door to door service.Application Audio, MP3, MP4, earphone, hearing aids, surgical instrument etc..RemarksAll parts ... quotation.We are looking forward to our Win-Win Cooperations!! custom sound volumn knob