High-strength USA made ACU-Carbon with uniform spine technology. Pre-Installed Microlite nocks are lightweight and indexable. Includes all-new 6.5 Inserts (23 grains) with 4x more protective shoulder and added F.O.C. Straightness:  +/- 0.003″. Weight: 300 spine, 9.5 gpi | 340 spine, 9.3 gpi | 400 spine, 8.4 gpi | 500 spine, 7.3 gpi.