Three-ring connector / possible incompatibility:  This cable worked fine when I connected my QC 15s to my iPhone, but it did not work when I connected my QC 15s to other devices through my headphone extension cable: [[ASIN:B0015ZIS8K RiteAV 25 ft. 3.5mm Extension Cable]]  I suspect that the incompatibility was due to this cable having a differently built connector than the original Bose cable.