Building off of the heritage of the Nano-XR, the Nano SST is an ultra-slim diameter shaft designed specifically for recurve bows. The Nano SST features Tri-Spine technology, with three specific spine areas with the stiffest being in the mid section of the shaft and the weakest spine configured to the back-end to allow for proper fletching clearance through the shot on a recurve bow. Nano SST has an ultra-slim parallel shaft profile that dramatically reduces cross-wind drift and is the ideal arrow for FITA, NAA and NFAA long-distance field shooting. Engineered for optimal velocity, strength and consistency, the Nano SST is constructed from 30-ton carbon so it will not take a set bend and ensures faster recovery out of the bow and superior downrange accuracy shot after shot. Straightness: 0.002", Weight tolerance: 1.0 grains, Spine selection tolerance: 0.002". Available spines: 1000 (5.11 gpi), 900 (5.57 gpi), 800 (5.88 gpi), 750 (6.38 gpi), 700 (6.46 gpi), 650 (6.95 gpi), 600 (7.33 gpi), 550 (7.79 gpi), 500 (8.18 gpi), 450 (8.97 gpi), 400 (9.62 gpi).