National Multi-Mini Nuc .
The nuc can be divided into four mating hives, each containing three frames. Each nuc has it’s own entrance as well as it’s own space in the crown board for feeding. It can also be divided into two or three larger nuc’s.
These half frames slot together to create one frame which fits directly into a national brood box. Meaning queens can be transferred directly from nuc into hive.

Alternatively, these frames can be slotted together and the box can be used as a 6 frame nuc.