Zebra Strings feature the patented Z-S Counter-Twist Technology. The strands in the Z bundle are twisted counter-clockwise while the strands in the S bundle are twisted clockwise. The two opposing bundles are then twisted together. When you draw your bow, the Zebra string has no twist bias and therefore pulls back straight, virtually eliminating peep sight rotation. Zebra Hybrid and Barracuda Strings are both made out of BCY 452X string material.