Leupold mounts are every bit as rugged and dependable as the Leupold optics they're intended to secure. With a huge variety of mounting systems, for nearly every type of firearm under the sun, you're sure to find the perfect match for you firearm, and your style of shooting. The Leupold steel standard bases and rings are the most versatile of any mounting system we offer. The rear ring is secured by windage adjustment screws, allowing the scope's internal adjustments to be reserved for precise sight-in. Additionally, shims can be used for gross elevation adjustment, reserving the scope's elevation adjustment for bullet drop compensation dial applications.