What is Duplex?
Duplex is that the radio has two frequencies per channel, often called a frequency pair. One frequency transmits while the other receives. It is a concept used to help explain Half Duplex and Full Duplex.
Half Duplex - operates as duplex with two frequencies, but in this mode the radio must switch between transmitting on one frequency and receiving on another. It can only do one at a time.
Full Duplex - full duplex uses two frequencies - one for transmit and one for receive - simultaneously.
Below is the duplex radio headset RayTalk made:
RHS-1519A- R1P for Maytel/Multicom Duplex radio
RayTalk can provide a wide range of radio accessories, any further questions please feel free to contact us!