I have used a wide range of harmonica cases over the past two decades, and this is by far THE BEST. It is very compact, well-constructed, and easy-to-use. I have it filled with a set of 12 Seydel Session Steels. My harps are easily accessible and are well-protected. The case is compact enough to fit inside a bigger bag or backpack.
I like it so much, I also bought one in the six-harp size!
(Dear Seydel: if you introduce a 15-harp version, I would buy that one as well... )