Soon to be released in the MAC Pro Sortiment are two brush containers.
Here is the promo text:
Any artist will appreciate the convenience of compartmentalized sections which allow for distinguishing between used and unused tools. Stores up to 16 brushes. Measures 2.5" diameter x 8.5" high fully extended (small). Stores up to 25 brushes. Measures 3" diameter x 8.5" high fully extended. (large).