Features: - Lenses and prisms made from optical glass material (BK-7) - Centre focus - Rubber coated / lacquered - Diopter adjustement - Tripod connection threads - Porro prism systems - Objective lens diameter: 40 mm - 8x magnification - Colour: black National Geographic 8x40 Porro Binoculars, Now we are going to get a little bit bigger. These classic 8x40 binoculars are able to show you observed details, even from a long distance very clear. Let your journey of discovery begin.