[Compatibility] Keuaaao X lighted nocks fit arrows with .204 inch inside diameter, compatible with standard bushings for easy installation. [Brightness] These arrow nocks emit a vibrant and highly visible light, making it easier to track your arrows during low-light conditions, including darker evenings and winter months. Ideal for monitoring arrow trajectory, improving shot accuracy, and simplifying arrow retrieval. [Easy On/Off] The light activates automatically upon release from the bow, featuring a bowstring-activated switch for reliable performance. A slider switch allows for easy deactivation. [Battery Life] Long-lasting LED illumination provides up to 48 hours of continuous use. The light remains highly visible even in bright daylight conditions. [Practicality] These lighted nocks are ideal for archery hunting, target shooting, 3D tournaments, and practice in various lighting conditions, including daylight, dusk, and low-light environments. Designed to help track flight path and locate arrows quickly. A valuable addition for archers seeking improved shot visibility. Color: Blue / Red / Green Material: Plastic Package Contents: 12 x Lighted Nocks for Arrows Note: Light reflection and display settings may cause slight color variation between the image and the actual item. Measurement may vary by +/- 1-3 cm.