The Alpha-Blaze is a one-piece Nock/LED unit that's bowstring-activated to provide the ultimate in arrow flight visibility. The one-piece Nock/led unit is index with the vanes and press-fits into the arrow's aluminum bushing. Upon firing, the bowstring's force compresses the two components and activates the LED. Anda |they're just as easy to deactivate. Simply pull the nock straight out until the light turns off. Super bright LED light provides superior arrow flight visibility Bowstring-activated, easy deactivation 24-hour battery life when activated Nock Retention Groove snaps into trigger box, allowing you to hear and feel positive engagement Eliminates the fit disadvantages and string wear associated with snap-on nocks Fits all TenPointA(R) & Wicked RidgeA(R) arrows with an HP Aluminum Bushing (sold separately) One-piece design, no assembly required Order today!