[Compatibilities] Keuaaao X lighted nocks fit arrows with .204 Inside Diameter, bushings matching and easy installation [Brightness] These arrow nocks emit a vibrant and highly visible light, making it easier to track your arrows during the winter holiday season and in darker evenings, helping you watch trajectory, enhancing accuracy and retrieval [Easy On/Off] The light comes on automatically when fired, and a slider switch allows for easy shut off; bowstring activated linear switch [Battery Life] Great battery life of LED lighted nocks: Up to 48 hours, the light remains very bright even in midday sunlight [Practicality] These lighted nocks for arrows are excellent for archery hunting, target shooting in the winter, in darker evenings, in bright daylight, and even in 3D tournaments, helping you watch trajectory and locate the arrow. They are a fantastic addition for any archer seeking enhanced shot visibility! Color: Blue / Red / Green Material: Plastic Package Contents: 12 pcs 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. The measurement allowed error is +/- 1-3cm.