Model Number: SB4 Gold 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 14,000 yen. It wasn't used frequently. Personal Impression: The rim is thin, making it an easy-to-play mouthpiece. *The shank has been modified, so please understand and accept no claims and no returns. Will be shipped in the original box.