they are a must for 3d, my friend does not use them and i have robinhooded 4 of his arrows at 3d shoots. i use carbon tech arrows hippo xp 26 & 3/4" long with pin nocks, 85 grain tips, my arrow weighs in @ 352 grains with 11.009 %
FOC. AND I JUST LOVE 'EM. THEY ARE EVEN ON MY CARBON EXPRESS CXL 350 ON MY HUNTING ARROWS.