Binoculars from Nikon Action Ex series are offering quite a lot for such a good price. The reason lies in their Porro prism system, which outperform the modern Roof prism system. Therefore the size of binoculars is a little bit bigger from other rivals, but on the other hand they are offering better light transmission rate and much more sharp and contrast image. They are designed for those who put optical performance at first place, before modern and compact size. The housing of Nikon Action Ex series is firm, robust and water sealed. They are also filled with dry nitrogen to enables the use at really low temperatures.