This is one of the worst wireless systems I have ever used/purchased. I purchased this to use with my high school music program, but there was so much static, interference, white noise, lost signals, etc. that is unusable. I even returned it to VocoPro for a replacement, hoping the one I got was defective. The replacement was just as bad. Even after placing the reciever less than 10 feet from the microphones, the problems persisted. To make matters worse, AA Duracell batteries do not fit. They are slightly longer than generic AA batteries, but the added length is too much for the unusally small tollerences in the battery compartment. Even generic batteries have to be forced in place. I ended up installing it in our theater for our administrators to use during staff meetings because no one seems to mind when they cannot understand or hear them talk. Do not waste your money.