AR Resonance, loved by world-renowned trumpet players such as Sergei Nakariakov and Randy Brecker. Top: MLE W 42 Bronze Silver Plate Backbore: 42 L Raw Brass Both are heavy types. There is some wear and tear, but there are no noticeable scratches or dents. Please make your purchase after judging from the photos and agreeing to the condition. Rim: Approximately Bach 1-1/2, wide rim Cup: Approximately Bach D to E Throat: Very wide. Because the cup is relatively shallow, you can easily reach high notes with a thick sound. The backbore is also thick, so it has a rather soft and thick character, and it's easy to produce airy, husky subtones. You can fully enjoy the appeal of AR. I think it's not as harsh as a Monette STC-3 and easier to handle. The volume also comes out quite a bit while maintaining a thick sound, so it's fun to play. It should fit without any problems on instruments with standard mouthpiece receivers, but on some instruments with thick receivers, the mouthpiece may bottom out, and adjustment with aluminum tape or the like may be necessary. Please be aware. (Shipping is not available from December 26th to December 28th, 2025. Shipping will be on December 29th. Thank you for your understanding.)