The different sized adapters make for a perfect fit on the arrows. Halo lighted nocks are constructed of ultra-strong, impact-resistant PC casting. Featuring a recessed switch design, the switches are easy to turn off, and they reliably turn on when I shoot them. These lighted nocks remain lit even when penetrating objects. The light is bright and easy to see, even during broad daylight. They are great for practice, you can see your shot and instantly tell exactly when you did something wrong. They are equally good for hunting. You can tell exactly where you hit and recover your arrow to begin tracking. They didn't cause any issues with my arrow balance or flight. You can enjoy uninterrupted illumination during your archery sessions, allowing you to track the trajectory and landing point of your arrow effortlessly. Lighted Nocks Are Crafted Using Premium Materials, Ensuring Durability And Long-Lasting Performance. Lighted Nocks Are Designed To Be Water-Resistant, Allowing Them To Perform Reliably In Wet And Damp Environments. No matter the weather conditions, you can trust these nocks to stay lit and guide your shots accurately.