Internal core unit for the MIAD Pistol Grip as well as the MOE, MOE Plus, MOE-K2, and MOE AK Grips. Designed to hold two (2) AA type batteries in a self contained, water resistant unit. Included internal spacer allows for rattle free storage of either (2) AAA or (2) N size batteries (commonly used for EOTech sights). Rubber cap has two sides with markings to identify spent batteries and can be opened with a push of the thumb.