Description: The model of the alto trombone mouthpieces It is computer-aided design system and computer controlled lathe work together to produce the most precise mouthpieces Trombone mouthpiece are suitable for students,intermediates and professional enthusiasts and beginners It meets worldwide standards and also approved by customers,teachers and musicians Best choice for you or giving your friends is a good idea Size Chart: Product Size: 8*3.8*3.8cm/3.15*1.5*1.5" Connector Outer Diameter: 1.1cm/0.43" Connector Inner Diameter: 0.9cm/0.35" Package Includes: 1 x 6 1/2AL Alto Trombone Mouthpiece