Matrix Battle Axe Retractable Stock for M4 / M16 Series Airsoft AEG Rifles (Color: Tan)

"Stock is well built out of a sturdy polymer, but the product page is a bit misleading. The "integrated battery storage" is for carrying spare batteries, as there is not a way to connect a battery from there. The stock can only accommodate batteries that fit inside the buffer tube. The "spare" tubes are standard diameter and 5 inches deep, meaning you battery and it's wires would need to smaller than that. My 2800 mAh Li-Ion sticks are too long to fit. The caps on these tubes are sealed with an O-Ring to keep water out which is nice.

DO NOT BE FOOLED by the tabs at the bottom, they ARE for removing buttplate, but that does not provide access to the buffer tube for installing a battery, you have to remove the whole stock to do that, which is admittedly smoother than most crane stocks.

Overall good product if you have multiple (3) short Lithium sticks that you swap out regularly. Not to be used with butterfly batteries, and not super useful if your sticks are longer than 4in, as you can only have one installed at a time.