The S-series porro prism binoculars have an objective lens diameter larger than 40 mm and are the continuation of the A-series. With the same high-quality coatings of the A series, impeccable image quality is guaranteed. Characteristic of this series is the high speed due to the large objective lens diameter. The S series offers many of the features of more expensive binoculars. Rugged with a solid rubber body, including the extra large center drive. They have exceptional optical performance with high quality BaK4 prisms. Multi-coating on all lenses; Die-cast aluminum body; Enhanced Light Transmission coating; Complete rubber lamination; Large center adjustment wheel; Click stop diopter adjustment;.