Introducing the US Army Alpha Black Flatline Barrel System. This system is now available complete or as a conversion kit for your existing US Army Alpha Black . The Flatline Barrel System is the first production back spin barrel ever produced. The principle behind the system is Tippmann's newly designed slightly curved barrel, which applies centrifugal force to the ball, creating backspin. Not only does this system offer increased accuracy and distance but also offers flat trajectory for thick brush and canopy play. By minimizing trajectory of the ball and increasing accuracy, you increase the amount of targets which would ordinarily be out of range. The Flatline Barrel System adds 100 feet of flat trajectory GUARANTEED.