Apollo is the all-carbon starter arrow with the tolerances and spine sizes needed to ensure a correct tune for every archer. Straightness tolerance: +-.005". Available in sizes 840 (8.4 GPI), 950 (6.2 GPI), 1070 (5.9 GPI), 1200 (5.5 GPI), 1400 (4.2 GPI), 1600 (3.8 GPI), 1800 (3.6 GPI), and 2000 (3.4 GPI). Components sold separately.