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. At first, it felt larger than I expected, but it became a mouthpiece that played well once I got used to it. It's also quite heavy. As the appearance suggests, the cup has a thick wall, producing a hard, less-likely-to-crack sound. There are scratches on the shank from attaching it to the instrument. Will be shipped in the original box.