This is a ALICE MOLLE adapter that was used in the US Air Force. The adapter allows the user to mount ALICE equipped pouches to MOLLE compatible surfaces. You mount the adapter to MOLLE surfaces. You can then clip ALICE clips to the slots on the outside of the adapter. This adapter allows ALICE gear to be mounted to MOLLE much more securely than mounting the ALICE clips directly to the MOLLE webbing.
This adapter is part of the Defensor Fortis kit.