Carbon Express 50756 Maxima RED Arrow with Dynamic Spine Control and Blazer Vanes, 350-Sized Red/Black Finished Shaft Hi-tech carbon material construction manages dynamic spine in a new way to make broad heads fly better Uses different carbon materials to control arrow flex to the Red Zone and make the broad head shoot more consistently Laser checked for straightness to a remarkable 1/10,000 of an inch Items specifications: 350-Size, 9.07-GPI, 0.342-inch Spine and 0.300-inch Diameter Breakthrough in controlling how an arrow flexes in flight to manage accuracy