The Sightron SIIISS624X50LRZSMOA features 6-24X magnification with an objective diameter of 50mm and tube diameter of 30mm. he fast focus eyebell allows for quick and easy adjustments in the field. The large oversized adjustable turrets in .25 MOA adjustments are resettable to zero and designed to withstand extreme weather elements. The side focus features parallax adjustment aimed for quick and easy adjustment and will focus from the minimum focusing distance to infinity. The zero stop rotating lock ring does not require any knob removal or shims. This rifle scope features ExacTrack windage and elevation adjustment system and Zact-7 fully multi-coated precion ground glass. This scope is also waterproof, shockproof, and nitrogen gas charged.