70° apparent field of view with 20mm eye relief. Waterproof for everyday use*, so you can use it without worrying about getting wet. [XW20] XW20: 70° apparent field of view with 20mm eye relief. Waterproof for everyday use*, so you can use it without worrying about getting wet. ■ A 70° apparent field of view and 20mm eye relief provide outstanding visibility and power. All products feature a 70° apparent field of view and 20mm eye relief. Enjoy powerful star images with a wide field of view. ■ New optical system for even higher performance. The optical system uses high-quality lanthanum-based high-refractive-index, low-dispersion glass. Advanced optical technology provides balanced correction of various aberrations. Particular attention is paid to spherical aberration in the pupil, reducing blackouts from the field of view for improved visibility. ■ Unique multi-coating for superior transmittance. PENTAX's unique multi-coating is used on all lens surfaces that come into contact with the air, and special coatings are applied to the bonding surfaces, achieving transmittance of over 90% across the entire visible light range (approximately 96% at 550nm). ■Advanced light-blocking technology, computer-simulated, positions the light-blocking aperture optimally. This achieves a higher-contrast field of view. ■Comprehensive lineup: A comprehensive, redesigned focal length for easy handling. From low-magnification stargazing to high-magnification planetary observation, this comprehensive lineup is suitable for all situations. ■Waterproof for everyday use* All products are water-resistant for everyday use, ensuring peace of mind even if they get wet during observation. *JIS Class 4 equivalent. Not suitable for underwater use. ■Sleeve size and eyecup mounting diameter are 31.7mm American size and 50.8mm 2-inch size. Removing the rotating eyecup reveals a 43mm diameter/P0.75 thread. XW20 ■Focal Length: 20mm ■Lens Construction: 4 Groups, 6 Elements ■Apparent Field of View: 70° ■Eye Relief: 20mm ■Mounting Diameter: 31.7mm ■Size (Maximum Diameter x Length): 61mm x 86mm ■Weight: 355g ■Manufacturer's Warranty: 1 Year