.61 Caliber Projectiles (purchased separately) 5-round Magazine (1 per Kit) Uses 8-gram C02 (purchased separately) Picatinny Rail Improved fiber optics sights for faster target acquisition Red-dot-ready universal bolt pattern Loaded chamber indicator PATENTED PULL-PIERCE TECHNOLOGY: CO2 is stored in the launcher unpunctured until the first trigger pull. On first trigger pull the CO2 is punctured and a projectile is launched simultaneously.