Pentax designed the 8x42 S-Series SD WP Binocular for a lifetime of rugged outdoor use in all weather and lighting conditions. The 42mm objectives are fully multicoated to reduce reflection and maximize light transmission through the entire optical path. Its roof prisms are phase-corrected to correct for chromatic aberrations ensuring bright and clear high-contrast images with true color rendition even in low-light. Its general purpose 8x magnification brings subjects close while maintaining a wide 60° angle 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 binocular sports a generous 21mm eye relief and its twist-up eyecups ensure comfortable viewing with or without eye wear. Protective coatings on the exterior lens surfaces repel water, dirt, and oil to keep them clean for unobstructed viewing.