TENPOINT PRO ELITE 400 CARBON ARROWS 20" AB 36P 20-INCH / 415-GRAINS / BALANCED AT 13% FOC / .003" STRAIGHTNESS 36-Pack with Alpha-Blaze Lighted Nocks. The Alpha-Blaze Lighted Nock contains a one-piece Nock/LED unit that is indexed with the vanes and press fits into the arrow's Aluminum Bushing. Upon firing the crossbow, the bowstring's force compresses the two pieces and activates the lighted nock. Deactivate the easy on/off Alpha-Blaze lighted nock by pulling the nock straight out until the light turns off no tools required. The LED light of the Alpha-Blaze system lasts for approximately eight hours when activated. The system features TenPoint's Alpha-Nock HP that is equipped with an HP Aluminum Bushing for increased strength and accuracy. The Pro Elite 20-inch carbon arrow is fletched slightly offset and is fitted with a 46-grain aluminum insert, Q2i Fusion X-II 3.0 Vanes, and TenPoint's new Alpha Nock HP Nock and Alpha Nock HP Nock Bushing. Pro Elite shafts are inspected for straightness to within .003" and hand-sorted for weight tolerance to within 2-grains per dozen. TenPoint's 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".