This is a mouthpiece for alto horn made by Yamaha. Please refer to the website for specifications. https://jp.yamaha.com/products/musical_instruments/winds/mouthpieces/altohorns/additional_tab4364.html I purchased this last year and used it once in a performance. There is some discoloration, but I don't see any warping. If you would like, I can upload photos from different angles.