Features: - Super Strong Clear Polycarbonate Construction - Waterproof and Shock Proof - Available in Strobing or Non-Strobing Versions - Available Colors: Red Green Red/Green Strobing - Fits X H S and GT Arrows - H (white bushing) = Fits smaller diameter carbon .233 ID shafts - GT (black bushing) = Fits smaller diameter carbon .246 ID shafts - S (gray bushing) = Fits standard carbon .244 ID shafts - X (no bushing) = Fits smaller diameter carbon .204 ID shafts - Each nock in this package weighs approximately 25 grains - Delivers more than 20 hours of lithium-powered battery life - 2-Pack - Advancing the lighted nock design by which all others are judged Nockturnal Shift FIT lighted nocks take the simplicity and reliability of the worlds most dependable and user-friendly lighted nock to an entirely new level. Thanks to the external on/off switch the process of shifting an ultra-bright string activated Nockturnal lighted nock off has never been easier. Just slide the switch and the nock turns off. Its that simple! With 20+ hours of long-lasting battery life and a durable design these nocks are built to last and perform like none other. Constructed of an ultra-strong impact resistant polycarbonate casing that protects the super-bright LED lights Shift nocks deliver on what users have come to expect from Nockturnal lighted nocks. The patented string-activated piston-driven contact linear switch triggers the nock to illuminate immediately when the string is released and can be quickly turned off with the newly integrated external switch a true evolution in the worlds most reliable lighted nock system.