This is a soft case for a trumpet. I found it very useful for carrying just one trumpet when my usual double case was too heavy, but I'm selling it because I no longer need it after buying a new single case. It has a pretty large capacity, and I think you can fit plenty of items besides the instrument itself. When I used it, I had my mouthpiece, oil, tuner, pet sheet, and writing utensils in it, and there was still plenty of room. Although I don't necessarily recommend it, the case is large enough to store the instrument with the mouthpiece attached.