This is a Magpul Industries Accessory known as the MIAD/MOE Storage Core, model MAG059-BLK.
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(R)" and MOE AK Grips. Not compatible with the original modular MIAD grip (MAG050)
Features:
Holds an included 1/2 oz. reusable lubrication bottle
