Pentax Weatherproof XW 20mm Extra Wide Eyepiece w/1.25in Barrel

Designed for use with PENTAX brand spotting scopes and with astronomical telescopes with appropriate 1 1/4" or 2" focusers. Ideal for both ground and astronomical observations, this eyepiece features fully multi-coated lenses to increase light transmission and color quality, high-refraction lanthanum glass elements for high-resolution images with minimal aberrations, and JIS Class 4 weatherproof construction for durability. Engineered using advanced computer simulation design technology, this high-performance eyepiece provides 20mm eye relief.