Carbon Express PileDriver Pass Thru Extreme Small Diameter Carbon Arrow Shaft, 12-Pack Bare shafts come with Carbon Express exclusive TCX Nocks and PTX carbon steel half-out inserts (nock color may vary from image) Innovative PTX half-out insert reduces the impact of crosswind drift, and maximizing downrange kinetic energy for deadly performance Laser checked for straightness to a remarkable 1/10,000 of an inch; Straightness of +/- 0.0004-inches is a maximum measurement, not an average Item specifications: 250-Size, 9.36-GPI, 0.390-inch Spine and 0.266-inch Diameter 12-pack of grey finished shafts are sorted and matched by weight and spine for best-in-class consistency