Sightron SIII 6-24x50mm Long Range Riflescope SIIISS624x50D is fogproof, shockproof and waterproof. The Sightron S3 Scopes feature a 30mm one-piece main scope tube, made from high quality aircraft aluminum with a tube thickness that is over twice as thick as one inch models, to provide maximum rigidity. The Sightron SIII 6-24×50 Rifle 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. A European style fast focus eyeball accompanies all SIII SS Long Range Models. A quick turn of the eyebell allows the user to focus in a matter of seconds. Tweaking the eye focus is just a small adjustment away. And the Sightron SIII LR Riflescope features ZACT-7 seven layer multi-coating with precision ground glass. These lenses provide superior light transmission and resolution for the ultimate in performance.