Bach 7MV Commercial Trumpet Mouthpiece - Modified V Cup Medium diameter mouthpiece with a modified "V" cup. Provides a fuller sound than the "S" cup. Special backbore helps facilitate the high register. The Commercial series was designed specifically for lead trumpet players looking for greater depth of sound and volume when playing in higher registers. The Commercial series starts with a Classic cup, but uses a 27 throat, a 24 backbore and increases the outside mass.