These are Compact 10 50 Long Eye Relief binoculars - that is, 10 x magnification and 50mm diameter lenses which are perfect for astronomy enthusiasts. They are simple binoculars but with great potential. Its 5mm output pupil, its diopter adjustment and its low weight make them an option to consider for any amateur. High-quality binoculars companies Spinor Optics to use natural and tourist prism glass BaK-4. Good quality optics ensures high brightness and image clarity. Central focus & correction in the right eyepiece. Resistant rubber construction ensures long-lasting and comfortable use.