From The Designer (Milwaukee Dave):

Compact Organiser insert for M12 Fuel Multitool, this insert has the usual space for the tool and has 2 large areas for batteries and accessories for the top space there is also 2 bins which will allow a little more storage of accessories if required.

It fits in the 5-Compartment Organizer (48-22-8435).

We now offer latches to identify which tool is in which case.  Latches are offered at a discount if purchased with a matching insert and are sold by the pair.  The latch that comes with this insert says M12 MULTI TOOL.