Denis Wick tenor trombone aluminum practice mute

"Denis Wick practice mutes are perhaps the best teaching aids ever invented. Not only do they fulfill the need for the IN TUNE painless practice,so essential in the development of every young player and an indispensable "hotel mute" for professional, but they also make possible an enormous improvement in tone quality using the entire vital capacity as a vibrating air column by opening the throat spaces thorough playing loudly in the low register." -Denis Wick Made in England.