This is a custom mouthpiece by Andy Taylor, who makes custom trumpets after working at PAXMANN in London, famous for their horns. It's a universal fit type, so it can be used with instruments other than Taylor. It's a heavy model, so it produces a sound with a sense of weight. The sound doesn't diffuse around the receiver, and it feels like it resonates from a distance from the bell. I think it's a mouthpiece that allows you to produce high notes with a beautiful sound. It has a good response and resonance. It has a rich, authentic sound with a dense core. The inner rim diameter is about the size of a Bach 3C. It has a gentle V-cup shape, and the cup is about the size of a Bach E. It is the shallowest mouthpiece among TAYLOR mouthpieces. The throat is #24 (3.86mm). The backbore is about a Warburton 5. There are no major scratches, dents, or plating wear that would interfere with playing. Please feel free to ask if you have any questions.