Spikes Tactical STU5025R9S: The Spike\'s Tactical ST-15 LE upper line-up is designed as a fully Mil-spec compliant upper series for law enforcement. This same level of quality and performance is now available to everyone, all at a price range that is affordable to shooters of any budget. Each component is manufactured to Mil-spec standards. This model features Spike\'s Tactical 16\" with 1:7 Twist Mil-spec Barrel, M4 Barrel Profile, Carbine Length Gas System, ST Micro Gas Block, .750\" Diameter Gas Seat, Spike\'s Tactical Mil-Spec M16 Bolt Carrier Group, ST BAR rail system, and A2 Flash Hider.