Aimrite�s Pro Competition railgun differs from our Competition Carbon model by the barrel being built from a Carbon fiber and Kevlar weave. The integration of the Kevlar fibers significantly improves impact resistance and results in a truly robust railgun. The Competition's barrel has a wall thickness of .078� (2mm). This reduces flex dramatically when under heavy power which in turn results in more energy transfer to the spear shaft and most importantly, a more accurate shot. The shaft rides atop Aimrite�s integral track which also adds strength and rigidity to the barrel. The Pro Competition is designed to accommodate heavier twin 5/8� (16mm) bands while firing the more rigid spring steel European notched shafts. Shaft sizes include 6.6, 7 and 7.5mm. Each gun is individually hand assembled and tested with all precision engineered Aimrite components. Guns come "ready to use".