The Denis Wick Tone Boosters are designed to fit most mouthpieces to increase the mass or weight at the cup of the mouthpiece. This allows the player to get a bit more energy into the horn without additional effort. They also help stabilize the mouthpiece to make it easier to "lock in" to the notes.
Few companies know more about mouthpiece manufacture, design and physics than the Schilke Company. They make a complete line of excellent trumpet mouthpieces that work with any instrument but especially compliment their fine line of outstanding trumpets.