The Paraduba Double-Cup Mouthpiece gives you two mouthpieces in one.  The scientific reaming of the top cup furnishes the shallow cup which is necessary to secure the extreme high tones and they come with the greatest of ease, G a bad tone for many performers, comes true.  High Bb comes as effortless and with as great volume as G is ordinarily produced.  The extreme high tones, which occur occasionally in ordinary music and frequently in solo playing or in difficult passages, are produced more easily and with full volume because the shallow upper cup puts them within reach by increasing the performers range.