The Alpha-Blaze HPX Lighted Nock is designed with a seamless one-piece Nock/LED unit that aligns perfectly with the arrow's vanes and securely fits into the arrow's Aluminum Bushing. Activation occurs upon firing the crossbow, where the force of the bowstring compresses the components, illuminating the nock. To deactivate, simply pull the nock straight out until the light turns off. The LED light is engineered to last approximately twenty-four hours once activated, ensuring long-lasting visibility. The HPX Nock/LED unit is a single-piece design that requires no assembly, ensuring ease of use Exceptional resilience Crucial for crossbow hunting Necessary for operation with TenPoint rail-less crossbows, specifically models TRX 515 and TX 440 Approved for 515+ fps Equipped with a nock retention groove, this feature enables users to audibly and tactilely confirm the secure connection of the nock to the string on TenPoint rail-less crossbows Bowstring has been activated The LED light offers exceptional visibility for arrow flight Simple Deactivation Approximately 24 hr of battery life when activated Incorporates TenPoint's Alpha-Nock HPX, which is mandatory for all TenPoint and wicked ridge crossbows Compatible with all TenPoint and wicked ridge arrows featuring an HP aluminum bushing (available for purchase separately) Pack of 3 illuminated nocks