Bushnell PermaFocus Roof Prism Binocular Never needs focusing 305ft field of view Fully coated optics Perma Focus binoculars with 10x magnification and 42-millimeter objective lenses Fixed-focus operation dials in focus at any distance automatically Fully coated optics for improved clarity and light transmission Ergonomic rubber housing for a secure grip and shock resistance Designed for sporting events and nature observation; limited lifetime warranty