Great mouthpiece! This mouthpiece is named after the world-renowned trombonist, Christian Lindberg. Its distinctive rounded form is impressive. Cup diameter: 25.50mm Equivalent to Bach's 5G size. ⭐︎Personal Impression Because the throat is large, my initial impression was that "it takes a lot of air," but regardless of the instrument, the sound starts quickly and resonates strongly. Flexibility is also high. If you maintain a firm aperture and control your breath, in other words, if you approach it with the mindset of "doing something physical," it's a mouthpiece that allows for free musical expression. You can truly feel Lindberg's playing style and philosophy.