This pouch allows the use of a Large battery with most folding stock AEG's that are wired to the rear of the gun. This is great for those who want to keep the versatility of a compact gun without sacrificing the full capacity of a Large Battery! It has adjustable velcro straps for easy installation and if you need to remove it. The pouch can hold up to a large 9.6v sub C sized battery (9.6v 3300mah).