1Strong Versatility: 25 inch standard interface, strong versatility, suitable for all 25 inch astronomical telescopes and accessories. 233MM 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. 3FMC Coating Process: Using high quality optical glass, FMC coating process, small chromatic aberration, high light transmittance, low dispersion, clear image. 4Lens Barrel: The lens barrel is made of aluminum alloy, which is sturdy and durable, with internal matting treatment to reduce reflection. 5Foldable 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