Nano-Proâ„¢ is simply the best 100% carbon target arrow in the world! Designed for FITA, NAA and NFAA long-distance field shooting, the Nano-Proâ„¢ is engineered with incredibly light yet strong 46-ton carbon. Nano-Proâ„¢ arrows recover even faster out of the bow than the Nano-XRÂ® while delivering the flattest trajectory and superior down-range accuracy. It has the smallest diameter of any of our target arrows, nearly eliminating cross-wind drift. Unlike aluminum core arrows, Nano-Proâ„¢ arrows wonâ€™t take a set (permanent) bend, consistently holding their initial spine tolerance for several seasons. Advanced technology, extreme accuracy Straightness: Â± 0.0015" Weight tolerance: Â± 1.0 grains Spine selection tolerance: Â± 0.002"