Thank you very much for viewing. This is a Best Brass trombone warm-up mute. I purchased it about 10 years ago and used it quite a bit, so it has deteriorated overall. I cleaned (polished) it as much as possible, but the rubber parts have also deteriorated. However, it is still usable, so if you've been wanting to try one, why not give this a try before buying a new one? Please give it a try. Please consider this item, understanding that it is a used product.