The turbo echo to the extreme! In addition to the features of the EC-2018 Turbo, it has Cyborg™ Robotic Voice, Endless Echo™, Stadium Sound™, Double Talker™, and a richer tone quality that can be best described as studio quality. The Double Talker™ effect is a one time repeat instead of a fading echo. Like the EC-2018 Turbo, the EC-2018ETRA runs off of a 9 volt battery. Note: * The "Talk Back" feature does not work on all radios. If you have to plug your mic into the radio in order to hear the receive, then it will probably work for you. If you get receive sound without any mic plugged in, then the talk back feature will NOT work for you.