Carbon Express T1317 PileDriver Hunter Arrow with Built-In Weight Forward and 2-Inch Assault Vanes, 350-Sized Mossy Oak Brush Pattern Shaft, 12-Pack Heaviest arrow in the Carbon Express line to create maximum kinetic energy and greater knockdown power for ultimate penetration Fletched with 2-inch Assault low-profile performance vanes for maximum arrow velocity and greater accuracy Laser checked for straightness to a remarkable 1/10,000 of an inch; Straightness of +/- 0.0005-inches is a maximum measurement, not an average Items specifications: 350-Size, 11.3-GPI, 0.345-inch Spine and 0.308-inch Diameter 12-pack of "Mossy Oak Brush" pattern shafts are sorted and matched by weight and spine for best-in-class consistency