Variable eyepiece with 20-60x magnification. Very good for dynamic birding situations - it enables both scanning of the terrain and bird identification in razor-sharp detail. Swarovski 20 to 60 Eyepiece for ATS, STS, CTS Scopes. All eyepiece lenses are 100% watertight. The 20-60x zoom is in any case the only watertight zoom lens. The fully adjustable eyecup with its large diameter opens up the full field of vision even for eyeglass wearers, providing a very comfortable viewing feel. All eyepieces are fitted with an integrated, quick-release lens cover. The new S-lenses also come with the unique SWAROTOP coating for bright and contrast-rich images, whatever the light conditions. Functional temperature: -20 to +55 C (-4 to +131 F) Storage temperature: -30 to + 70 C (-22 to +158 F) S-eyepieces are watertight. Objective lens focal length: 460 mm (18.11 in). Eyepiece 20xSW, Eyepiece 30xSW, Eyepiece 45xSW, Eyepiece 20-60xS. Magnification: 20x, 30x, 45x, 20-60x.