Huntingdoor 12 Pack 400 Spine Carbon Fiber Arrows Archery 31-Inch with Changeable Tips for Compound Bow or Recurve Bow 12Pack of 31 inches arrows with strong, lightweight carbon shafts; improved wall thickness for added durability matched with replacement field points; optimal accuracy and target penetration,and nocks Colored plastic fletching & nock rounded permanent nickel-plated stainless steel tip perfect for target practice & outdoor shooting Shaft Diameter:7.6mm,Spine: 400 Extraordinary durability for extended use