The nitrogen-filled roof prism binoculars are waterproof and have a precise mechanism. The high-quality optics produce excellent image reproduction The 10x magnification is ideal for nature observers and the prisms are made of BaK-4 glass. The field of view at a distance of 1000 meters is 101 meters and the twilight figure is 20.5 Other features include LE eyepieces, mid-shoot focusing, twistup eyecups, and diopter compensation. A tripod connection thread is standard Dimensions 12.3 x 5.1 x 15 cm/weight 531 g Box contents: binoculars; nylon bag; shoulder strap; lens cap; eyepiece cap To adjust the focus, please look through your binoculars with your right eye closed. Now use the center wheel to adjust the image for your left eye until it is sharp and clear. Close your left eye and adjust the image for your right eye with the diopter ring so that it is also sharp and clear