Report "We use it for fitness classes. We've had this transmitter replace twice now and it will have to be replaced for a third time now. The first time it was a default in the receiver. We sent it back got a new one but this time it's the transmitter that's not working. The instructor teach an hour class and at the beginnig of the class you can hear the instructors lound and clear but after about half hour the instructor has to keep turning the volume up on our sound board and by the time the hour class is up the volume is at the highest it can be until not sound come through at all. The way to explain the problem it's like if we were using a low batterie, it gets weaker and then it just stops working because there's no juice left in it. IT that makes any sense!!"