Model Number: SB4 Silver Plated Gerd Seifert Model Inner Diameter: 17.00mm Throat Diameter: 3.7mm Cup Shape: U Cup, Tilz marking MF, slightly shallow Shank: American Purchased about 5 years ago for around 9000 yen. Personal Impression: The rim is thin, making it an easy-to-play mouthpiece. *Please note that the shank has been modified. Sold as-is, no returns or refunds.* Will be shipped in the original box.