Pre-Installed Smoke Micro Lite Nocks, MicroLite Inserts, multi-layer wrapped carbon fibers, super lite Carbon, High Precision manufacturing insures weight, straightness, and spine matches for every arrow in the dozen. Specialized carbon is used to produce the best quality high-velocity arrow available today. These can be used with bows 45-60 lbs. These arrows weigh 7.4 grains per inch and have a Spine Deflection of. They come with 360 degree rotating nocks and aluminum inserts at no charge.This shaft size will handle up to an 60 lb bow. And they are 32 inches long. 001/1000 and weigh within +/-2 grains of each other. The item "Easton Flatline Surgical 400 Carbon Arrow Shafts 1 Dz" is in sale since Thursday, April 26, 2018. This item is in the category "Sporting Goods\Outdoor Sports\Archery\Arrows & Parts\Complete Arrows". The seller is "bullseyefeathers" and is located in Cantonment, Florida. This item can be shipped worldwide.