STOCK UP and SAVE! Go to my store or “sellers other items” and type in “muzzleloader” to see more! New in the package Thompson Center Fiber Optic Rear Sight for round barrel New Englander and Black Mountain rifles. Complete sight in the packaging with mounting screws. Getting hard to find so get them before they’re gone. We pride ourselves in offering a variety of quality production, custom and aftermarket replacement parts and supplies for black powder builders, shooters and enthusiasts of any level.