Model Number: S20R20 Silver Plated Inner Diameter: 17.0mm Throat Diameter: 4.0mm Cup Shape: U Cup Shank: American Purchased about 2 years ago for around 13,000 yen. Personal Impression: I bought this for high notes. Despite the thick rim, it was easy to control. It felt bigger than I expected when I first started using it, but it became a mouthpiece that sounded good once I got used to it. It's also quite heavy. As the appearance suggests, the cup has thick walls, making it less prone to sound distortion and producing a hard, clear tone. There are scratches on the shank from attaching it to the instrument. Will be shipped in the original box.