Wicked Ridge Match Alpha Nock 400 Spine Carbon Arrows - 3 Pack - Alpha-Nock features a deep bowstring groove, a large smooth radius base, and elongated ears. The string on TenPoint's crossbows wraps tightly around the center of the Alpha-Nock to yield straight nock travel and precision down-range accuracy, while minimizing string serving wear. The Alpha-Nock's deep groove "holds" the bowstring in place on extremely narrow crossbows to prevent "shoot-over" or "shoot-under".