1. ED extra low dispersion glass. 2. Coaxial dual speed focusing dials for quickly achieving and clarifying the image. 3. Fully multi-coated green film lens and Bak4 porro prism. 4. Variable 25x - 75x focal zoom magnification. 5. Nitrogen filled Waterproof, fog proof, shock-proof performances. 6. The retractable sun shade. 7. 45 degree angled eyepiece. 8. Adjustable eye cups. 9. With tripod and smartphone adapter.