The Real Avid Master-Fit AR-15 Crowfoot Wrench Set allows you to use one ratcheting wrench to accomplish all the normal functions needed to assemble or maintain an AR-15. Simply pop off one crowfoot style head and replace it with another and you are ready to go! Tighten or remove castle nuts or spanner nuts, flash hiders, barrel nuts and more! Includes torque limiting, ratcheting wrench and a hard polymer case.