This is the classic tuba mouthpiece, the Helleberg II by Schilke. I've heard it's the so-called third generation model, created when Karl Hammond was with Schilke (this is just a guess, so please take it with a grain of salt). I don't know the exact specifications, but it's a very responsive mouthpiece. Also, it's been plated, so it feels good on the mouth, and the sound is softer and more resonant than with standard silver, allowing you to enjoy a wonderful sound! Thank you.