The Sightron S-TAC3-16X42MOA Rifle Scope features 3-16X magnification with an objective diameter of 42mm and tube diameter of 30mm. The fast focus eyebell allows for quick and easy adjustments in the field and the precision adjustable target turret adjustments are in .25 MOA and are protected by rugged windage and elevation caps. A pop up style zoom ring lever allows ease of use in cold weather climates. This rifle scope features ExacTrack windage and elevation adjustment system and Zact-7 Revcoat that features fully multi-coated precision ground glass. This scope is also waterproof, shockproof, and nitrogen gas charged.