Musket sight protectors are made out of brass. They come in different sizes for different muskets. Size #1- 2 Band Enfield, #2- 3 Band Enfield & 61 Springfield, #3- Zouave & 1855 Springfield Rifle, #4- Mississippi Rifle & 2 Band Springfield, #5- Enfield Musketoon, 59 Sharps Carbine, 63 Sharps Carbine, Berdan Sharps Rifle & Infantry Sharps Rifle, #6- J.P. Murray Carbine, #7- Smith Carbine, #8- Gallagher Maynard. The Sight protectors tighten around the barrel over the sight to keep anything from moving it. Once you have your musket sighted, use a sight protector to keep your musket accurate all the time.