Carbon Express Predator AIR 6mm Arrows Shafts 400 Spine 12 Pieces Black. Its forgiving platform supports straightforward tuning while the carbon construction is designed for long-lasting strength. Manufactured with 360 degree spine consistency each shaft is built to deliver uniform flight characteristics from arrow to arrow. Straightness is rated to +/- 0.025 inches max with a +/- 2.0 grains weight tolerance for dependable repeatable results. Specifications for Carbon Express Predator AIR 6mm Arrows Shafts: Manufacturer: Carbon Express Color: Black Fabric/Material: Carbon Quantity: 12 Diameter: 6 mm Features of Carbon Express Predator AIR 6mm Shafts: 6mm Standard-Diameter Hunting Arrow Shaft Balanced Speed And Durability Forgiving Tuning And Dependable Performance Across Setups Straightness: +/- 0.025 Inches Max Average Straightness: +/- 0.002 Inches Weight Tolerance: +/- 2.0 Grains Components: 5mm Aluminum Sleeved 2-Piece 40 Gr Inserts Size (Spine) GPI: 300 (.305?) 8.6 Size (Spine) GPI: 350 (.304?) 8.0 Size (Spine) GPI: 400 (.333?) 7.2 Size (Spine) GPI: 500 (.391?) 6.2 Available in sizes: 300 350 400 500 Package Contents: Carbon Express Predator AIR 6mm Arrows Shafts Carbon Express CX05802: Predator AIR 6mm Arrows Shafts 400 Spine 12 Pieces Black