Cornet mouthpiece, Denis Wick 3B, gold-plated finish. Inner diameter: 16.75mm Throat: 4.27mm This was included as a bonus when I purchased a cornet. It produces the quintessential cornet sound! However, I'm selling it because the inner rim diameter doesn't suit me. I've used it only a few times for testing. There are some minor scratches, so please refrain from purchasing if you are concerned. It doesn't come with a box, so it will be shipped in simple packaging. No returns or exchanges, please.