Denis Wick Bass Trombone Extending Tube Mute Denis Wick Bass Trombone Extending Tube Mute £59.50 Quantity: at £59.50 each Add To Basket 1 in stock. 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 trombone and bass trombone models are particularly good in the usually difficult low register.