CA12CD Push to Talk Amplifier - SPECIAL ORDER. A cordless PTT (push-to-talk) headset adapter designed to provide encrypted communications and PTT functionality for applications such as Public Safety Dispatch and Air Traffic Control. It works with all H series headsets, and utilizes digital processing (DECT) while operating in the UPCS radio band . Quick Disconnect facilitates use with Plantronics H Series headset tops Designed for people on the move.On a train, on a plane, from your computer to your bedroom, PSB headphones are lightweight and ready to pack up anywhere you want to go. Fold em up into the protective travel case and youll never be far from true hi-fi listening. We even added a thoughtful touch for your comfortdual input connections on either side of the headphones means no more crossed wires. Just plug in the cable on the left or right and be within easy reach of a headphone jack no matter where its situated.All of the music. None of the noise.Sometimes you just want it to be just you and your music in your own personal space. The PSB M4U 2 Active Noise Cancelling Headphones dont let anything come between you and enjoying your music. Thanks to PSBs exclusive Room FeelTM technology, your music will sound so rich and natural youll think youre listening to a set of high-end loudspeakers.All of the music. Non-stop.The M4U 2 model features three convenient modes of operation: Active Noise Cancellation (ANC), Active Mode, and Passive Mode (without batterie