The Flatline is a barrel system designed for the Tippmann Model 98 and Tippman A-5 paintball markers. What makes this particular barrel unique is that it curves upward in a flattened S-shape.
This unorthodox design lends extraordinary distance and accuracy, making this the perfect barrel for sniping. The barrel operates on the principal of using rotation to produce lift. The curvature causes the paintball to leave the muzzle with topspin, and centrifugal force works against gravity to keep the ball aloft.
The barrel is fairly easy to install, but when doing so, be very sure to line it up correctly, because if you don't, your shot will slice or hook. Velocity is also an important factor, because at velocities too low one cannot achieve the barrel's full effect, and at velocities too high your shot will take a sharp turn upward before striking your target.
If the marker is turned sideways, the ball will curve sharply opposite the way the marker is turned, allowing one to effectively shoot around trees and bunkers.
At $120, the Flatline is one of the more expensive barrels out there. I have found, however, that the extra distance and accuracy is well worth it. I have scored hits on players that I was well out of range of.