Kelly mouthpieces are designed to make playing brass instruments easier. The terrors of braces, college and professionals facing inclement weather marching, or during the holiday season, well worry no more!!! Kelly mouthpieces were designed to meet the demands of brass players from beginners to professionals by making it easier and more comfortable to play. This design is one of Kelly's own, and is their best seller! All cup sizes are sampled by their professional staff and are adjusted to produce the final, comfortable, easy-blowing mouthpieces. All of their mouthpieces are identical to exacting standards. Experience why teachers are switching to plastic!!!