Lancer Tactical Airsoft Rifle Gun M4 370 - 395 FPS Gen 2 EVO 10" RIS Airsoft AEG - GRAYOverview: Upgraded Gearbox Internals Lancer Tactical took the internals of their line of first Generation M4 rifles a step further to deliver more POW in its power! A quick change spring gearbox can be used to change your FPS from CQB to Outdoor MilSim on a whim, its ported piston head maintains excellent air compression inside the cylinder, and the integrated 6. 03 mm tightbore barrel gives you the range and precision you'd never expect from similar