The LiPoSaver does exactly what it should. I put him in a pretty fast and loud flying wing and the alarm is perfectly audible. Even at high altitude it sounds, as if he were standing next to a dirkt. But you should set it a little lower because the voltage drops a little at full throttle and the saver then relatively starts early. But after two test flights have been the perfect setting found. I have to say that I just installed it with Velcro on the wing. How good it is audible in the fuselage of an aviator, I can not judge therefore. But I think it will still be more than adequate.