1、Strong Versatility: 25 inch standard interface, strong versatility, suitable for all 25 inch astronomical telescopes and accessories. 2、33MM Focal Length: Using 2 groups of 4 optical structures, 33MM focal length, 52 degrees large field of view, comfortable viewing, easy to find the target. 3、FMC Coating Process: Using high quality optical glass, FMC coating process, small chromatic aberration, high light transmittance, low dispersion, clear image. 4、Lens Barrel: The lens barrel is made of aluminum alloy, which is sturdy and durable, with internal matting treatment to reduce reflection. 5、Foldable Eyecups: Folding eye mask design, not easy to get tired after long time viewing, you can watch a wider range of nebulae, star clusters, landscapes, moon surfaces, etc. 1 x Astronomical Telescope Eyepiece Item Type: Astronomical Telescope EyepieceMaterial: Aluminum Alloy, Optical GlassInterface Specification: 1.25inFocal Length: 33MMField of View: 52 DegreesExit Pupil Distance: 16mmLens Coating: FMCOptical Structure: 4 Elements in 2 GroupsThread Specification: M 28.5x 0.6mm