Feature: 1. Focal Length: This is the 20mm or 0.8in focal length telescope eyepiece, superior performance for comfortable observation. 2. Film Coating: This astronomy telescope eyepiece is with full multilayer coating, optical glass, provides maximum brightness, high clarity. 3. Features: All metal, the bottom thread of this telescope eyepiece can be for adjustable 1.25in filter, for use with standard 1.25in interface telescope(not including) or filter(not including). 4. Large Field of View: Very comfortable for observation. Astronomy telescope eyepiece is not only with high brightness but also large field of view. 5. Application: Astronomy telescope eyepiece is suitable for all astronomical telescopes (31.7mm or 1.25in interface). Used for astronomical observation of lunar surface, planets, nebulae, star clusters, dispersing nebulae and others. Specification: Item Type: Astronomical Telescope Eyepiece Material: Aluminum alloy, optical glass Focal Length: Approx. 20mm / 0.8in Interface Size: Approx. 31.7mm / 1.25in. Package List: 1 x Eyepiece 1 x Storage Box