Double Drum Magazine M4/M16 3000rd

3500rd Drum Magazine. Fits most of the M4/M16 series excluding Tokyo Marui Next Gen. BBs are fed electronically via help of 9V battery. There are two options available for the feeding. The first one is always feeding with out any touch of a button etc. The second way is via sound which operates when the gun is fired upon, the magazine will feed automatically the BBs due the sound/noise of the gun.