[Compatibility] Keuaaao X lighted nocks fit arrows with .204 inch inside diameter, compatible with standard bushings for easy installation [Brightness] These 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. Helps in observing arrow trajectory, improving accuracy and retrieval [On/Off] Light activates automatically upon release, with a slider switch to turn off. Bowstring-activated linear switch for reliable and simple operation [Battery Life] Long-lasting battery life: up to 48 hours of continuous use. LED remains bright even in midday sunlight [Practicality] Ideal for archery hunting, target shooting, 3D tournaments, and practice in various lighting conditions, including dawn, dusk, and bright daylight. Enhances shot visibility, trajectory observation, and arrow recovery. A valuable addition for any archer seeking improved shot tracking Color: Green Material: Plastic Package Contents: 12PCS x Lighted Nocks for Arrows Note: Light reflection and different display settings may cause slight variations in color appearance. Measurement may vary by +/- 1-3cm