Willie's Trombone Mouthpiece Aquarius (6-1/2 size / Inner diameter approx. 25.4mm) 【Features】 Developed in collaboration with Hiroshi Odagiri, principal trombone player of the Tokyo Metropolitan Symphony Orchestra. Based on the 6-1/2 series, tuned for modern use: easy to control and responsive. Neutral tone that is easy to shape: ideal for students stepping up or general use. Willie's long-selling standard series. 【Recommended Points】 Well-balanced design that is easy to choose as a standard model. Balances ease of playing and tonal range. Perfect for transitioning to your first custom mouthpiece. 【Specifications】 Inner Rim Diameter: Approx. 25.4mm (6-1/2 series) Model: Aquarius (Standard Finish) Application: Tenor (Compatible with standard 6-1/2 shank)