Carbon Express Mayhem Carbon Arrow Shaft, 12-Pack Bare shafts come with LAUNCHPAD Precision Nocks and BullDog Nock Collars (nock color may vary from image) Features K-360 Degree Weave Technology -patented process that integrates a carbon weave into the back section for added strength and spine consistency Laser checked for straightness to a remarkable 1/10,000 of an inch; Straightness of +/- 0.0035" is a maximum measurement, not an average Item specifications: 350-Size, 9.8-GPI, 0.334-inch Spine and 0.302-inch Diameter 12-pack of black finished shafts are sorted and matched by weight and spine for best-in-class consistency