Soulo Mute is perfectly in tune in all registers (including pedal tones) has no back-pressure and no squirrely notes. The coated brass clips are flexible so as to accommodate all bell sizes and to allow for quick on and off. It is considerably lighter than all other brands on the market. Soulo Mute offers two adjustable positions each of which allow for different colors in the sound. It now comes with a 100% organic cotton bag to protect it from wear and tear and provide a third sound color option and it behaves like a darker bucket mute with the bag stuffed inside. This allows the trombone player to blend perfectly in a section comprised of different brands of bucket mutes. It works great for performance and sound recordings as it will never fall off the bell.