Carbon Express Predator AIR 4mm Arrows 400 6 Pk 1006848. Each shaft is produced with 360-degree spine consistency to promote uniform flex and repeatable launch behavior from arrow to arrow. Straightness is held to +/- 0.025 inch max with an average straightness of +/- 0.002 inch and weight tolerance is +/- 2.0 grains. The arrows are finished with Q2i Fusion Shield-Cut vanes and include 4mm aluminum 50-grain outserts. Specifications for Carbon Express Predator AIR 4mm Arrows: Manufacturer: Carbon Express Color: Black Size: 400 Features of Carbon Express Predator AIR 4mm Arrows: 4mm micro-diameter shaft profile 360-degree spine consistency Straightness:+/-0.025 inch max Average straightness:+/-0.002 inch Weight tolerance:+/-2.0 grains Q2i Fusion Shield-Cut vanes Includes 4mm aluminum 50-grain outserts Available in 300 350 400 Package Contents: Carbon Express Predator AIR 4mm Arrows