Great stash spot - Magpul MIAD/MOE Core Storage

Great little water-resistant stash spot for batteries, ear plugs, etc. I use the AA/AAA core on all my guns, as it's the largest core, and fits plenty more than just batteries. I'll typically store a set or two of ear plugs, a coin battery for the red dot, and a lens cloth. I wouldn't submerge the thing and expect it to keep out water, but it should be fine for a quick dunk or whatever rain can throw at you.