All scopes in the SIII series feature a 30mm one-piece Main-Tube made from high quality Aircraft aluminum. Tube thickness is more than twice as thick as one inch models to provide maximum rigidity. All models are fogproof, shockproof and waterproof. Large oversize Tactical knobs with 1/4 inch adjustments are standard on all models. All models feature Tactical knobs that are re-settable to zero. All Tactical knobs are exposed and designed for use without Windage and Elevation caps. This scope features the ultimate in all weather construction. They are waterproof, nitrogen filled and provide a lifetime of internal fog protection for inclement weather. This scope features Sightron's unique ExacTrack windage and elevation adjustment system. No other system on the market comes close to the precision and performance of ExacTrack. Specifications: - Magnification: 16X - Object Diameter: 42 - Eye Relief: 3.6 - Click Value: 1/4 MOA - Fov: 6.5 - Length: 13.19 - Tube Diameter: 30mm - Windage Elevation Travel: 150 - Weight: 19.40 - Finish: Matte Black - Minutes Per Revolution: 15 - Target Knobs: Yes - Sunshade Included: No - Adjustment Objective: Yes, Rear Adj. Ring - Minimum Focus: 10 Yds - Adjustable Objective: Yes (10 yards to infinity) -Fully Multi Coated: Yes (Zact-7 TM 7-Layer)