Yukon 10-4x56 Sightmark Tactical Riflescope w/Mil-Dot Reticle The Sightmark Triple Duty riflescope uses cutting edge glass and lens coatings to ensure that it is the most accurate tactical instrument on the market. Precision multicoated optics are the distinguishing feature of the Sightmark Triple Duty riflescope line; multicoated lenses offer the clearest view for easy target acquisition in both bright and low light situations. Both waterproof and fogproof, the nitrogen filled Sightmark Triple Duty line features oversized windage, elevation and focusing adjustment knobs for easy adjustment in the field. Locking mechanisms on the windage and elevation adjustments provide an additional level of accuracy and ensure that the scope stays zeroed. The internal lit mil-dot reticle helps shooters to successfully make highly accurate shots over a wide range of distances.