With porro prism design and anti-reflection coated lenses and large light throughput these binoculars are intended primarily for marine use. An individual focusing function that, after adjustment for your individual eyesight, gives you the freedom to directly focus on a desired object without manual focusing! Perfect in rough seas. Rugged, robust and of course waterproof. If you should be unlucky enough to drop them in the water, ETERNA Marine II will float!Protective cover in signal yellow plastic.