Arrangements to adapt hands free headphones for use on both ears

Full Title

Details of transducers, loudspeakers or microphones covered by H04R1/00 but not provided for in any of its subgroups > Details of earpieces, attachments therefor, earphones or monophonic headphones covered by H04R1/10 but not provided for in any of its subgroups > Arrangements to adapt hands free headphones for use on both ears