For: Intellect 8.4v 4200mAh NiMH Large BatteryProduct Information:
I bought this battery from a military surplus store and I was very pleased with it once I replaced my old windhorse battery. I lasts long and increased my rpm a little and my fps. I hae used it in my AK ever since... or at least until my AK died, but whatever, that's life. Anyways, I hope you enjoy this product as much as I did. Completely worth the money!
Increases gun's performance
Not really any, it's a good buy