From their announcement:
The next item for the M3619 Folding Unit Structure System is now out!
The large FUS is workshop/warehouse sized, with a footprint of 7.25 x 7.375 inches and a height of 2 inches, and is scaled for use with 28-30mm figures.
This model has a removable roof with functional interior, and includes 8 different color schemes, parts of which may be mixed and matched for up to 64 possible combinations.
The large FUS is priced at $6.00.