MGCR: G&G's First GBB Airsoft Rifle Series New Innovative GBB System Design Featuring Groundbreaking Features Aluminum Construction Billet-Style Upper & Lower Receivers Aluminum M-LOK Handguard Windage & Elevation Adjustable Front and Rear Flip-up Iron Sights High Precision CNC Barrel Group Assembly with 6.04mm Brass Inner Barrel with O-ring Stabilizer Double Teflon O-ring Nozzle Assembly Full-Steel CNC Constructed Modular Trigger & Fire Control Group Light-Weight CNC Aluminum Bolt Carrier Group Functional Forward Assist Button Steel Constructed Buffer CNC Aluminum Buffer Tube with Reinforced Castle Nut Assembly Lightweight High Performance 30 Round Gas Magazine Mock Gas Piston that Actuates when Firing 45 Degree Selector Enlarged Magazine and Bolt Release Ambidextrous Charging Handle, Magazine Release, and Selector QD Sling Mount on the End Plate G&G's AR/M4 GOS-VZ-Stock Textured Vertical Pistol Grip Adjustable Hop-Up Available in 7"Inch, 10"Inch, 12"Inch This product is only compatible with gas designed specifically for Airsoft guns. Do not use lighter fluid or butane gas, as that will cause permanent damage.