The TSN-99 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-99 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-99 Prominar Spoting Scope: Pure fluorite crystal objective lens100% magnesium alloy structureCompatible with Kowa System accessoriesDual focusNote: an additional eyepiece is required to operate. Kowa TSN-99 PROMINAR 99mm Fluorite Crystal Lens Straight Spotting Scope TSN-99S