Ideal for land or sea, these binoculars are Nitrogen-filled to prevent fogging, and are waterproof for up to 10 minutes in 0.5m of water. Field of view: 348ft @ 100yds/116m @ 1000m. The Bak 4 lenses operate under a central eye focus system to provide a clear view, and the non-slip rubber grips allow for comfort and secure holding. Flexible rubber eyecups provide protection to the lenses when not in use, and a carry case is supplied to ensure all-round protection when stored.