What is this Thing?

[[OmAc] Loki]

Nice simple question... What the hell is this thing and how do I use it? (see link to d2_prison_070003.jpg)

http://www.onemanarmycorps.com/Files/d2_prison_070003.jpg

 

[WhiteZero]

Thats ammo for the secondary fire on the iRifle.