Altra Arrows 166 Phantom Premier Arrows .001in 350 Pack of 6 Black. Built with an advanced lightweight carbon layup they deliver exceptional speed durability and consistency. Each shaft is verified to a .001 inch straightness tolerance and incorporates NO SPINE technology for improved tunability and uniform flight. Premium aluminum titanium and stainless-steel components enhance performance while each pack is weight-matched to +/- 1 grain. Each set includes the Phantom A.R.C.O.S. insert/outsert system and nocks. Specifications for Altra Arrows 166 Phantom Premier Arrows: Manufacturer: Altra Arrows Color: Black Fabric/Material: Titanium Stainless Steel Carbon Aluminum Quantity: Pack of 6 Shaft Length: 32 in Fletching: Shafts Straightness: 0.001 in Features of Altra Arrows Altra Phantom Premier Arrows: Micro diameter carbon construction Straightness tolerance: .001 inches Premium aluminum titanium and stainless components Length: 32 inches Weight matched to +/- 1 grain Includes Phantom A.R.C.O.S. Insert/Outsert System and nocks Spine sizes: 250 (9.8gpi) 300 (8.5gpi) 350 (8.0gpi) 400 (7.1gpi) 500 (6.2gpi) Package Contents: Altra Arrows 166 Phantom Premier Arrows Altra Arrows AA-166Y350A: 166 Phantom Premier Arrows .001in 350 Pack of 6 Black