The revolutionary McKinney II shaft allows archers to reach their maximum distance with less poundage than ever before! This extremely fast arrow will give you speed beyond your wildest dreams. With speed comes flat trajectory and flat trajectory allows less wind drift. Rick spent over three years working on the precision required to satisfy archers who want ultra-precise and ultra-fast products. The super high tech, space-age carbon used in each shaft allows for the lightness with extreme exactness. The McKinney II shafts are the most precise arrows shafts made today. SIze/Spine Weight Length Recommended Point Weights 450 6.5 gpi 32" 80-100 grains 500 6.1 gpi 32" 80-100 grains 550 5.7 gpi 32" 80-100 grains 600 5.4 gpi 31" 70-90 grains 650 5.1 gpi 31" 70-90 grains 725 4.8 gpi 31" 70-90 grains 850 4.5 gpi 30" 60-80 grains 950 4.2 gpi 30" 60-80 grains 1050 3.9 gpi 30" 60-80