This is a Bach 24AW Megatone type, a standard tuba mouthpiece. This model adds even more overwhelming power to the soft, deep tone of the 24AW, resulting in a sound with presence. It produces a sound that stands out even in large orchestras. I believe this mouthpiece will fit most large tubas, including Yamaha rotary tubas. It has been carefully stored, so while there are some minor scratches, it is in quite beautiful condition. This is a rare mouthpiece, so please consider purchasing it. Thank you for looking.