Carbon ExpressA(R) Maxima Red Arrow Shafts represent a breakthrough in controlling dynamic spinea |how much an arrow bends when shot. The high-tech Tri-Spine/Red Zone design has stiffer ends that contain the arrow's flex to what's called "the red zone," resulting in tighter groups and superior accuracy with broadheads. 100% carbon fiber construction Front 1/3 features BuffTuff Plus outer layer construction for excellent strength and spine consistency Middle 1/3 features BuffTuff construction, the world's toughest and quietest carbon arrow finish Rear 1/3 features Diamond Weave construction for ultimate stiffness Tri-Spine/Red Zone technology controls oscillation Q2i Rapt-X 2" vanes BullDog nock collars with Launchpad precision nocks Launchpad precision nocks for controlled arrow release Pack sets are sorted & matched by spine and weight Spine sorting tolerance: +/- .0025" Weight sorting tolerance: +/- 1.0 grains +/- .002 real straightness