Carbon Express Maxima XL 27 Arrow Shafts 300 Spine 12 Pieces Black. Tri-Spine Technology supports stable launch and predictable flight for tight groups in high-pressure shooting. 360 degree spine consistency keeps each shaft behaving identically to reduce tuning variables and maintain uniform tracking shot to shot. Straightness is rated to +/- 0.025 inches max with a +/- 1.0 grains weight tolerance and it includes 12 Bulldog nock collars. Specifications for Carbon Express Maxima XL 27 Arrow Shafts: Manufacturer: Carbon Express Color: Black Fabric/Material: Carbon Quantity: 12 Features of Carbon Express Maxima XL 27 Arrow Shafts: Largest Legal Diameter Indoor Arrow Shaft Built For Indoor Target Competition Tri-Spine Technology Stable Launch And Predictable Flight Characteristics 360 Degree Spine Consistency For Uniform Shaft Behavior Straightness: +/- 0.025 Inches Max Average Straightness: +/- 0.001 Inches Weight Tolerance: +/- 1.0 Grains Includes 12 Bulldog Nock CollarsOther Components Sold Separately Package Contents: Carbon Express Maxima XL 27 Arrow Shafts Carbon Express CX05819: Maxima XL 27 Arrow Shafts 300 Spine 12 Pieces Black