I have used the Airline 77 system for years. My headset got a short so I had to order a whole new system. It was delivered very quickly. So excited to have a new system that will stay on my head. Very disappointed that the one switch is hid inside the battery compartment. It is hard to know when it is on or off. There is no light to indicate. I find I have to tap it to see if it is off or I. When I have a substitute they won’t be able to figure it out. After two days of use I have already had to change batteries. It’s making me bummed about the whole system.