This 401 mute bag is actually big enough for a bass trombone straight mute. A removable partition with velcro ends fastens anywhere in the bag to surround your mute. The bag still has room for water bottle, eye glasses, etc. Music folder fits in the outside pocket. Everything all in one compact package. Very impressed with this bag. It should last a lifetime.
This bag is the second one we have purchased. There are some minor changes to the style that make this bag even better than the first one. On the inside there is a removable partition that adheres anywhere inside, not just top and bottom. Also there is a cushioned inside floor plate which was not on the first one. On the outside, there are sewn in straps for the backpack kit (available separately). This is one of those bags that you can use a million different ways. You are not going to find a better bag out there, especially at this price. Highly recommended.