This is a Warburton backbore 11. It's a popular vintage model, and the shape is different from the current ones. It's a thicker backbore among Warburton models, producing a very orthodox, thick, and soft tone with a defined outline, offering a well-balanced sound. It's suitable not only for classical music and wind bands, but also for situations where you want depth and thickness in your sound with lead-type cups or medium cups, or when you want a convincing tone for solos. It has a core sound that doesn't get muddy and has good projection, unlike the AR Resonance series. The evenness across the entire range is also excellent. There are some spots where the plating appears to be lifting. There are no issues with actual use, but please refrain from purchasing if you are concerned about this. Please assess the condition from the photos and purchase with your understanding.