| 20090161893 | HANDHELD TRANSMITTER/RECEIVER - It is intended to provide a handset that can communicate clear conversations and that is superior in serviceability, even in work environments where wearing a helmet is required or in conditions where wearing a helmet or mask is required, such as when riding a two-wheel vehicle, performing construction work, or the like, and that includes a bone conduction speaker and a laryngophone that are detachable. The handset includes a bone conduction speaker | 06-25-2009 |