Carbon Express Tank 23D 55 spine Carbon Arrows - 12 Pack - Industry leading front and rear end durability ensures your quiver will be stocked full of TANK 23D arrows through the entire season. Combining this durable build with industry leading consistent 360 degree spine means this arrow will not only find the bonus rings, but has the toughness to endure those rear impacts when the competition goes for your nocks! The most accurate arrow to ever hit the 3D scene is offered in three spine sizes to accommodate shooters of all sizes. Proprietary Diamond Weave - Unparalleled spine consistency BullDog Nock Collar - Unrelenting strength and durability for nock-end impacts Straightness: +/- 0.0025in Weight Tolerance: +/- 1.0 grains Spine Selection Tolerance: +/- 0.002in