The TSN-99S Prominar Spotting Scope delivers high optical performance in a compact package. It features a large 99mm objective lens made of pure fluorite crystal, which is paired with a Kowa XD concave lens to provide ample light transmission even in the failing light of early dawn and late dusk. These lenses, combined with a series of improved optical lens coatings virtually eliminates chromatic aberration at high magnification. The TSN-99S is also equipped with a dual focus mechanism to quickly and smoothly bring your subject into detail with just a few revolutions. In addition, the this spotting scope is 100% compatible with the Kowa System accessories including different eyepieces, as well as the digiscoping adapters for DSLR cameras and smartphones. Features of the TSN-99S Prominar Spoting Scope: Pure fluorite crystal objective lens 100% magnesium alloy structure Compatible with Kowa System accessories Dual focus Kowa TSN-99 PROMINAR 99mm Fluorite Crystal Lens Straight Spotting Scope w/TE-11WZ II 30-70x Zoom Eyepiece TSN-99S-ZK