[Compatibilities] Keuaaao X lighted nocks fit arrows with .204 inside diameter, bushings matching and 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 in observing trajectory, enhancing accuracy and retrieval [On/Off] The light activates automatically when fired, with a slider switch to turn off. Bowstring-activated linear switch for easy operation [Battery Life] Long-lasting battery life: up to 48 hours. The LED light remains very bright even in midday sunlight [Practicality] These lighted nocks are excellent for archery hunting and target shooting in winter, low-light conditions, bright daylight, and 3D tournaments. They assist in tracking arrow trajectory and locating arrows. A fantastic addition for any archer seeking enhanced shot visibility Color: Green Material: Plastic Package Contents: 12PCS x Lighted Nocks for Arrows Only the above package content is included; other products are not included Note: Light reflection and different displays may cause the color of the item in the picture to appear slightly different from the real thing. Measurement may vary by +/- 1-3cm