Extremely light weight and compact Extra low-dispersion fluoride glass Phase-corrected Schmidt-Pecan prisms* fully multi-coated optics Protective LotuTec lens coatings Asymmetric closed-bridge configuration Nitrogen-filled, water and fogproof Nitrogen-filled, waterproof, fogproof Off-center knurled focusing wheel Black Finish Magnification 10x Effective Lens Diameter, mm 25 Exit Pupil Diameter, mm 2. 5 Twilight Factor 15. 8 Field of View (FOV) @ 100yds, ft. 291 Apparent Field of View, deg 54° Close Focus, ft. 6. 2 Diopter Adjustment Range +3 | -3 dpt Exit Pupil Distance, mm 16. 5 Pupil Distance, mm 35-72 Lens Type FL Prism System Schmidt-Pecan LotuTec / Nitrogen Filling Yes / Yes Water Resistance 100 mbar Operating Temperature, °F -4 / +145 °F Length, in 4. 4" Width, in 4. 5" Weight, oz. 10. 9