Radical Firearms RF-15, Semi-Automatic, AR, 300 Blackout, 16 Barrel, 1:8 Twist, 15 RPR MLOK Handguard, Anodized Finish, Black, Olive Drab Green B5 Pistol Grip andB5 Stock, 1 Magazine, 30 Rounds FR16-300HBAR-15RPR-ODG The Radical Firearms 16 inch HBAR Contour 300BLK AR rifle uses MIL-STD Upper and lower receivers along with the 15 inch RPR free float rail system for increased accuracy, keeping your hands cool, and giving you plenty of room for accessories. Regardless if it's your first or fiftieth, a Radical Firearms AR rifle will not disappoint!