Monophonic and stereophonic headphones with microphone for two-way hands free communication

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 > Monophonic and stereophonic headphones with microphone for two-way hands free communication