Bose 20ft Extension Cable for Bose Headphones. Bose 20 foot Extension Cable for Bose Headphones, Expand your listening area and increase your freedom of movement with this extension cable compatible with QuietComfort 3 Acoustic Noise Cancelling headphones compatible with QuietComfort 15 Acoustic Noise Cancelling headphones compatible with Bose on-ear headphones compatible with Bose around-ear/ in-ear headphones