I have 2 Audio-Technica AT 813 Electric Condenser Mics. These mics are in good working condition. They each use 1 AA battery and have on/off switches. I bought these new in the late70's. I only have 1 case. The other one is around here somewhere. I still have the spec sheet that came with these new. They come with the cords and mic holders. They worked really good when recording live. The voice windscreens are perfect ( not bent up) $200 O.B.O.