The straight view of the STS 80 is particularly beneficial to those who need to find moving targets quickly. The 80 mm objective lens diameter provides higher detail recognition, while a wider exit pupil ensures brighter images and comfortable viewing even in poor lighting conditions.This scope is the Lens Body Only. It goes great with either of the Swarovski Oculars: 25-50x or the 20-60x.Anyone looking for equipment of proven quality right from the start will be delighted by the spotting scopes in the ATS/STS range. They offer all the features that you would look for in a spotting scope, including a large field of view for rapid target acquisition and tried-and-tested optics. Features:Effective objective lens diameter (mm): 80Eye relief (mm): 17Shortest focusing distance (ft / m): 16.4 / 5Diopter correction at (dpt): > 5Objective filter thread: M 82 x 0.75Functional temperature: -13 degF to +131 degF (-25 degC to +55 degC)Storage temperature: -22 degF to +158 degF (-30 degC to +70 degC)Submersion tightness: 13 ft (4m) water depth (inert gas filling)