Denis Wick (5507) Trombone Extending Tube Mute. Denis Wick 'E.T.' mutes are well engineered 'Wow' mutes of traditional design. They all work well with tubes either in, extended, or removed. The E.T. (or Extending Tube) mute is also known as the Harmon Mute, WaWah and BuzzWow mutes.
