Material design provides for high-end customization and configurations onto the airsoft rifle. M1913 Mil-Spec rail system with 37 slots. Flip-Up front and rear sights are made out of reinforced polymer that are compatible with standard M4/M16 airsoft guns. Sections in the rail mount are integrated into the polymer handguard at the 3, 6 and 9 o'clock positions. Multiple control options include fire selector, magazine release, and a monopod adapter that's built in. Durable CNC machined one-piece upper receiver. Lower receiver is made out of reinforced polymer. Quick change barrel system without the need of using tools.Specifications: Operation Green gas Build CNC Machined Upper Receiver / Polymer Lower Receiver, Front & Rear Sights, Magazine, Stock Firing Modes Semi-auto, Full-auto, Safety mode Muzzle Velocity 360-380 FPS Magazine 38 rounds (0.20g BBs) Outer Barrel 333.24 mmInner Barrel 370.84 mm Hop-Up Yes, Adjustable Weight 8.1 lbs Overall Length 31.75 Folded / 34.75 Total 1X Airsoft Masada Rifle