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. The SV Series feature exposed large locking Tactical Style Turrets that are 1.5 inches in diameter. Offered in 0.25 MOA adjustments the turrets pull for up for windage and elevations adjustments and push down to lock preventing unintentional movement from occurring in the most extreme environments. Sightrons patent pending F.A.S.T. (Fine Adjustment Sight Tuner) focusing system offers the shooter precise focal adjustments for precision shot placement. Two dial adjustments offering a fast focal adjustment and a fine (4X) focal adjustment for ultra-fine parallax and focus correction.