The MIAD/MOE Lube Bottle Core is an internal grip core that holds an included 1/2 oz. reusable lubrication bottle. Comes standard with the MIAD GEN 1.1 Grip, the Lube Bottle Core also works with the MOE, MOE-K2, and MOE AK Grips. Not compatible with the original modular MIAD grip (MAG050)