Equipped with the ACU-X Lighted Snap-On Nock, the 20-inch, 440-grain lighted ACU-X arrow features a high-performance carbon shaft and a new precision spine-indexing manufacturing technique – placing the spine of the arrow in the exact configuration that has been tested and proven to perform best specifically for our rail-less forward draw crossbows, delivering the ultimate in consistency and long-range accuracy out of this platform.