Eye relief 16 millimeters Lens coating description: Fully Multi-Coated Item weight: 98 grams Water resistance level: Waterproof Focus type: Fixed focus 20mm focal length and 66-degree ultra-wide angle provide a wide field of view suitable for observing the lunar surface, planets, binaries, and bright nebula interiors 5 elements in 3 groups with FMC green film deliver sharp images with good color correction and contrast; blackened aluminum 1.25" eyepiece barrel reduces internal reflection and provides a crisp image Folding rubber eyecup allows comfortable viewing and blocks stray light to enhance image brightness 16mm eye relief enables close eye placement to the lens without interference from eyelashes and is ideal for eyeglass wearers Includes two protective caps for eyepiece protection, easy carrying, and storage