This Hydra Stripped Modular Lower comes with an AR Interchangeable Magazine Well and offers the ability to change Magazine Wells on your Lower Receiver to accommodate whatever caliber you want.  Leaving it as a Stripped Lower allows any AR-15 Mil-Spec Stock and Fire Control Group (FCG) to make it complete. Ideally suited for use with the Hydra® Quick Change Barrel Upper Receiver (QCB-D), where you can change calibers by switching out barrels as well.  This is a Stripped Modular Lower Receiver and only includes an AR Interchangeable Magazine Well.