Trombone Mouthpiece LS-48S YAMAHA Rim Inner Diameter (mm): 25.25 Throat Diameter (mm): 6.62 With a very well-balanced rim and cup, this mouthpiece is all-around. It has the ability to meet the advanced demands of professional musicians and is highly refined. Please take a look at the photos and make your purchase after understanding and agreeing to the condition. YAMAHA Trombone Mouthpiece Takkyubin Compact (Delivery Service)