Tokyo Marui 7.2V 500mAh Micro Battery for 18C AEP Series.

"It works as well as you'd expect a battery to. I stuck it into my CYMA AEP M9 handgun and it works. It is slightly shorter than the CYMA version I got with the pistol, but that was just something I noticed rather than a gripe.

"I fried my old battery so I needed this new one. 500 mah, way better than the TM 200 mah and the 450 mah ones have problems.