The Best Brass "PotStop" is a stop mute whose non-transposing feature is truly one-of-a-kind. This mute allows you to play stopped using your regular fingerings. It works for F, Bb, F/Bb double horn, and now even for Vienna horns.
When Best Brass first developed the Non-transposing stop mute back in 2003, the concept itself was actually for students. However, it was accepted primarily by professionals and is currently used in many major orchestras such as Vienna Philharmonic Orchestra.
Some features of this newest model are based on conversations with the players who have used the previous Non-transposing mutes for years, such as Mr.Wolfgang Tomboeck from the Vienna Philharmonic Orchestra.