TruGlo Muzzle Brite Xtreme Sights can be the perfect replacement for stock sights. The Muzzle Bright Sights offers great accuracy, are easy to install and will make any muzzleloader happy. Extreme Sights are a reliable and dependable addition to the TruGlo Fiber Optic Night Sights family of products. Combining top-notch and uncompromising quality with an affordable price, the TruGlo X-Treme Sights can fulfill your outdoor needs while still offering a great value for the money. Universal mounting system for in-line muzzleloaders CNC-machined Full windage and elevation adjustment Front diameter is .040 in. Rear diameter is .029 in. Endorsed by the Rocky Mountain Elk Foundation