I’ve been a fan of Fusion instrument bags for a long time now, using them daily to carry all of my instruments from building to building as I teach elementary band. Until now though one major instrument has been missing from their line, a bag for a bass trombone.
The main reason I have liked the Fusion line of instrument bags is that not only are they roomy, well padded, and easy to carry, they also have the special Fuse-On connectors that let you connect one bag to another to make them easy to carry. I used to fuse my trumpet backpack with a clarinet/flute bag and carry four different instruments around in one combined package. The bass trombone bag also has these connectors, and can be combined with other bags such as the Fusion backpack or their Fusion iPad bag.
The bass trombone bag itself can hold a trombone with a bell of up to 10.5 inches in diameter. The slide is kept inside the bag in its own special sleeve that is removable and padded as well. One of the demo photos I saw makes it look as though it is even big enough to hold a standard trombone stand as well.