[Compatibilities] Keuaaao X lighted nocks fit arrows with .204 inside diameter, bushings matching for easy installation [Brightness] These nocks emit a vibrant and highly visible light, making it easier to track your arrows during the winter holiday season and in darker evenings. They help monitor trajectory, enhancing accuracy and retrieval [Activation] The light activates automatically when fired, with a slider switch to turn off. Bowstring-activated linear switch for reliable performance [Battery Life] Long-lasting battery life: Up to 48 hours of illumination. The LED remains highly visible even in bright daylight [Practicality] These lighted nocks are ideal for archery hunting, target shooting in low light, bright daylight, and 3D tournaments. They assist in tracking arrow flight and locating shots, providing enhanced shot visibility for any archer Color: Green Material: Plastic Package Contents: 12 pcs x Lighted Nocks for Arrows Note: Light reflection and different display settings may cause slight color variations between the image and the actual item. Measurement may vary by +/- 1-3 cm