Instead of sticking an ear piece in your ear, the radio plays the caller over the speaker and you talk into the microphone. Personally, I don't really like the quality.
Mi do, however, love the All-In-One BlueTooth headset that works with your cb and phone. I've been using it with all my setups, Optima, Galaxy, Cobra. Just plug in the 4 pin BlueTooth box to the radio mic jack and you're done. To talk, press the PTT button and talk into the headset like you're on the phone b the sound quality of the microphone is fantastic. It sounds as good as the astatic 636, ranger 198 an better than the new road kings.
CbRadiosPRONTO