Eterna 7x50 Marine BinocularsWith porro prism design and large light throughput these binoculars are intended primarily for marine use. Perfect in rough seas. Rugged, robust and of course waterproof. If you should be unlucky enough to drop them in the water, Eterna Marine will float! field of view 116m floatable lens diameter 50mm magnification 7x nitrogen prism type BAK4 waterproof Protective cover in signal yellow plastic Waterproof, nitrogen gas filled Very good night vision