For M15 Series AEG Rifle.
For those who don't like the low capacity standard AEG Magazine.
It is a winding magazine that is perfect for military simulation games and most national operations.
Having a non-winding magazine also means you will need a way to load your magazine with a speed loader.
Can make you hold the gun more stable. 
This Hi-Cap Magazine is a direct replacement of the Standard one.
400 Rounds of loading capacity are enough for most competition & skirmish airsoft game.
Large thumb dial on bottom of magazine allow you to wind up the compression spring.
Open Case Design let you very easy to refill the BB Bullet.
Weight(Gram):207