This is a silver-plated LASKEY "59E" mouthpiece for euphonium and large-bore trombone, made by the American mouthpiece maker LASKEY. Inner rim diameter: 25.9mm Cup depth: DEEP Throat diameter: 7.11mm This mouthpiece is made by Mr. Laskey, who became independent after making mouthpieces for the company Silky. The mouthpiece offered here is a re-edition made after his passing. With its deep cup and not-so-wide throat, this mouthpiece is easy to control and produces a warm sound. There are some scratches from use, but it is in quite good condition!