#1 Patented Piston System -Lifetime Warranty -Manufactured in USA -Short -Stroke Free Floating Piston System -Harmonics Not Transferred into Barrel -Self-Cleaning -Carbon & Gases Expelled Away from Shooter -Bolt Carrier -Group & Other Critical Parts Remain Clean & Cool -Adjustable Gas Settings -Technologically Advanced Coating Processes -Corrosive Resistant -Preserves -Integrity of Night Vision.