SVBONY 25mm telescope lenses 4-element plossl design for astronomy telescope; fully multi coated broadband green film optical glass and approx 52 degree filed of view for broad field lunar observations Comes with sturdy plastic case-proect the eyepiece from dust and moisture Fully-multicoated achromatic design: Eliminate chromatic aberration and increase lens permeability to get bright views with impressively high contrast 4 element broadband green film optical glass: Premium symmetrical Plossl optical glass lens gets excellent aberration correction and extremely high resolution rivaling 25mm eyepiece with standard 1.25"interface: M28.5x0.6mm filter threads fits for any standard 1.25" telescope eyepiece filters or devices to the moon or celestial bodies 40 degree apparent field of view: Broad-field lunar observations of the Moon;planets;medium-sized star clusters;cloudy nebulas Blackened lens edges and blackened interior: The inside of the adapter is fully threaded to minimize reflections to reduce scattering of stray light and maximize contrast Specifications: Type: Plossl eyepiece Focal length: 25mm Barrel size: 1.25"/31.7mm Apparent field of view: 40-Deg Filter threads: M28.5x0.6mm for Standard 1.25" filter Coatings: fully multi-coated Lens elements: 4 elements Lens groups: 2 groups Blackened lens edges: yes Height: 72mm/2.82in Rubber eye guard: yes Package includes: 1xSVBONY 1.25" Plossl 25mm multi coated eyepiece