Echo Master CB Base Mic. Powered by nine volt battery. This is not just any old cb radio base station echo microphone. If you can find one you will find the echomaster a bit of a rare classic. Besides having a clever meter, the microphone has an electret mic element. This is not common. This gives this mic more of a computer mic sound. This gives it quite a broad range of frequency range compared to conventional cb microphones. Even if you do not like to use echo, the echo master mic I believe is the MC-60 of cb base mics.