There's nothing fantastic about the modular styling of the Unit Portables. There's a main bag and two smaller pouches that you can attach using a rather elegant hook-on system. While the creator's website tries to make it out into a big deal ("clever numerical system blah blah"), it really isn't. But the bag itself? Ah, precious.
Designed like a cross between a shopping bag and a portrait messenger, it's arguably one of the most good-looking bags I've seen in a while. Plus, there's colors -- many colors, so you can pair a brown bag with yellow and green pouches to get away from the drab blackness of everyone else's accessories.
Unit Portables label each bag component separately. Unit 01 stands for the actual laptop bag, which comes with a detachable shoulder strap and cut-out carrying handle. The two hook-on pouches are Unit 02 and Unit 03, respectively. I can't get a real perspective on the size, although, the bigger pouch should be able to house your adapter and the smaller one can probably hold a mouse.
Inside the main unit is a sewn-in laptop sleeve that can fit laptops up to 15 inches in size, with some extra space left for books and documents. In case you're not into putting the pouches outside, the hook-on strips are available inside the primary compartment, too, so you can use those small zipped pouches in there to keep the interior stash organized.
Availability for the Unit Portables appears to be restricted to one store in Stockholm for now (you can see it on a map in the website). No pricing information is listed.