The 3-pack of Alpha-Blaze Lighted Crossbow Nocks are ingeniously designed with a one-piece Nock/LED unit that aligns perfectly with the vanes and securely fits into the arrow's Aluminum Bushing. When you release the crossbow, the force from the bowstring compresses these two components, activating the lighted nock. Turning off the Alpha-Blaze lighted nock is a breeze; simply pull it straight out until the light goes off. The LED light in the Alpha-Blaze system has an impressive duration of approximately twenty-four hours when activated, ensuring long-lasting visibility and making it an excellent choice for low-light conditions and tracking shots.