Hi Wiliam i have one of those they are great if you want to do bit mouthpiece of practice and don’t want to get the whole neighbour hood upset, you can use it anywhere.Also what may be of interest to you something i also use, a Warburton P.E.T.E. Embouchure Trainer and that makes no noise at all, these things are real cool and they work for me anyway,you can have one in your pocket and use it absolutely anywhere. hope that helps William.
paddy