Designed to have a higher front of center for better down range accuracy and penetration. Standard diameter arrow shaft made from 100 percent carbon with the Rugged Wrap process. Straightness tolerance of +-.004â?쳌. Available in sizes 300 (9.1 gpi.) 350 (7.9 GPI), 400 (7.4 GPI), and 500 (6.5 GPI). Includes nocks and 50 gr. brass inserts.