Carbon Express Maxima Red Shafts Dozen are a breakthrough design in controlling dynamic spine for better arrow flight and improved broadhead accuracy. Different stiffness and wt. properties over the length of the shaft work together to contain the flexing of the arrow to the Red Zone. Includes LaunchPad precision nocks, inserts and BullDog collars. Per 12. Straightness factor:.0025. Wt. tolerance:1.09 gr. Recommended field point size:19/64. Size Spine GPI Dia. Stock Length 250 .250 8.1 .295 31.5 350 .350 9.1 .300 31.5