Built with Gold Tipâ??s Smart Carbon Technology, the light-weight Velocity Pro features extremely tight straightness and weight tolerances. Delivers the same consistent performance as the Hunter series, but with increased speed. Straightness tolerance of +-.001â?쳌 and weight tolerance of +-0.5 grains. Available in sizes 600 (5.9 GPI), 500 (6.3 GPI), 400 (7.4 GPI), 340 (8.2 GPI), and 300 (8.8 GPI). Includes GTO nocks with bushings and inserts.