The green laser can be unlocked with 110 kills or buying it with 310 CR.
You can attach this on all primary weapons, for a boost to accuracy and hip-fire/aiming stability statistics.
The laser allows you to see exactly where your bullet will land. (not including bullet drop)
The green laser is the counterpart to the red laser.
- The main difference between red and green lasers, is the mounting position. The green laser is usually mounted for more accuracy, though on some PDW's I have noticed better accuracy with the red laser.