Modern rifle scopes must meet the demands placed upon them in an operational sense, as well as satisfy consumers. It's not always easy to do both, but U. S. Optics has come up with a winner in their new "B" Series, which includes the B-10, B-17, and B-25 scopes. The B-10 is a medium-range scope, meant to engage targets out to a range of ~1,000 - 1,200 yards. The B-17 is a medium-long range scope, meant to engage targets out to a range of ~1,500 - 1,700 yards. Finally, the B-25 is a long-range scope, meant to engage targets out to a range of ~2,500-yards (and potentially further) in the hands of a capable marksman. Though the general rule of thumb is 1x magnification power for every 100-yds (approximately) range between the shooter and the target, there are certainly scopes with low-grade lens materials that can make successfully engaging a target at moderate- to long-distance a real challenge. Not so with the B Series. U. S. Optics utilizes premium lenses and materials in the construction of these scopes, sealing them against the elements. A series with premium features and numerous reticle options, U. S. Optics' B-series scopes are destined to find their way on to precision rifles owned by the most discerning operators and competitors. The new B-10 optics have these popular features. Features: Locking elevation and windage knobsZero-stopRevolution counterTool-less elevation zero2 mm Exit Pupil Diameter+2 to -3 Diopter2” / 50.80 mm Objective Lens Housing Diameter1.40” / 35 mm Ocular Lens DiameterLithium Coin battery (CR2032); runtime up to 8,000 HoursThe B-10 optics also have all the same durability, reliability, and performance that US Optics is known for. Additionally, this Anti-Reflective Device fits B-10 scopes and will block stray light rays from entering the objective lens, reducing glare in the process. Specifications: US Optics 1.8-10x40 .1mrad GAP B-10 GAP