Designed for a lifetime of rugged outdoor use, Pentax 8x40 S-Series SP WP Binoculars can be used with confidence in all weather and lighting conditions. The 40mm objectives are fully multicoated to reduce reflection and maximize light transmission through the entire optical path without making them overly cumbersome for a long day on the trail. Utilizing the traditional porro prism configuration gives scenes a rich depth of view for an immersive observation experience and provides a comfortable feel in the hand with a lot of surface area to maintain a sure grip. The coatings ensure bright and clear high-contrast images even in low-light, and their utilitarian 8x magnification brings subjects close while maintaining 363' field of view to preserve situational awareness. Complementing the optical performance are construction details made for the trail. The optical tubes are nitrogen-filled and O-ring sealed for fogproof performance and to make them submersible to as much as 3.3'. The binoculars sport a generous 20mm eye relief and the fold-down eyecups seal against the ocular cavity to block stray peripheral light which can dim images.