Improvements to Renuzit Trumpet Mute

Improvements to Renuzit Trumpet Mute: " Although I'm a very beginner, I realized, that 'the original renuzit mute' plays badly out of tune. This was confirmed by my teacher, a professional trumpet player. The mute raises the pitch of some notes, perharps due to shortening the bell. To make it play in tune, I removed the 'plug', that closes the top of the container (on the side, that is pushed into the horn)"