to communicate just like on a regular telephone, and Simplex headsets which are affordable PTT (push-to-talk), two-way radio systems. Select the wireless series below that best meets the needs... or remote antennas. They allow coaches to communicate just like on a regular telephone. Simplex Wireless systems are based on traditional push to talk operation. When a coach... coaches communication systems. We manufacture a full line of wired systems along with both simplex (push to talk), and full duplex (simultaneous talk) wireless headsets. ...