Alexander 22 horn mouthpiece. I don't know when I bought it, it was a long time ago. It's been over 10 years. Outer diameter: 25.0mm Inner diameter: 17.5mm Throat bore: 4.0mm Cup depth: 28.0mm Rim: 3.75mm The condition isn't bad, but it's old and shows signs of use. Please consider this item if you understand that it is a used product.