Quite simply, the War Lock replaces the barrel nut on almost any AR-15. Once replaced, it allows the user to remove and install barrels without tools. This modularity allows the AR-15 owner to change out over 90 calibers by switching simple components (typically a barrel, bolt and/or magazine).
NOTE: Other rifle makers want to sell you a single caliber, or proprietary system. We put the decision making in your hands. You can create the AR-15 that is made for you, without the barriers that come standard from other companies. Every person is different, and we feel that choices should be left to the individual.