1、IMPROVED COMPATIBILITY: These lighted nocks are specially designed for arrows with a 6.2mm inner diameter, ensuring a perfect fit and accurate installation. 2、DURABLE CONSTRUCTION: Crafted from plastic material, these lighted arrow nocks are built to withstand the toughest conditions. They offer exceptional durability and a long lasting performance. 3、EFFORTLESS OPERATION: With a user friendly design, these lighted nocks are incredibly easy to use. Simply attach them to your arrows without the need for any tools, and enjoy hassle free experience. 4、AUTOMATIC ILLUMINATION: The built in LED lights in the tail of these lighted arrow nocks automatically illuminate upon release, providing a clear and visible path for your arrows, even in low light conditions. 5、VERSATILE ACCESSORY: Not just a practical tool for nighttime situation, these lighted arrow nocks also serve as a valuable accessory for quick arrow location during daylight hours, making them perfect for all scenes. Item Type: Lighted nocks Material: Plastic Weight: Approx. 20g / 0.7oz Battery: 1 x CR425 button battery 25mAh(included) Tail Diameter: 10mm / 0.4in Main Tube Diameter: 6.2mm / 0.2in Length: 4.3cm / 1.7in Length(without shaft): 3.8cm / 1.5in 5 x Lighted Nock