Item Type: Aspheric Eyepiece Material: Aluminum alloy Application: HD full coated telescope accessory Type4mm 62 Aspheric Eyepiece 1.25in10mm 62 Aspheric Eyepiece 1.25in23mm 62 Aspheric Eyepiece 1.25in Focal Length4mm / 0.16in10mm / 0.39in23mm / 0.91in Vision626262 Fitting DiameterStandard 1.25in / 31.75mmStandard 1.25in / 31.75mmStandard 1.25in / 31.75mm Lens Diameter0.39in / 10mm0.39in / 10mm0.87in / 22mm CoatingOptical Lens, Fully Coated High DefinitionOptical Lens, Fully Coated High DefinitionOptical Lens, Fully Coated High Definition The Structure of The Optical SystemAspheric EyepieceAspheric EyepieceAspheric Eyepiece1The product is made of high quality aluminum alloy, can be used for any 1. 25 inch astronomical telescope and concentrator. 2For lens with the same refractive index, 62 aspheric eyepiece are more thin and light than spheric eyepiece, and are mainly used for planetary observation. 3The wide angle 62 aspheric eyepiece can obtain the maximum detail and clarity in the entire field of view, and obtain almost distortion free images. 4This eyepiece provides high magnification, looks closer and more detailed, for viewing the moon and planets. 5With anti loss design, the groove part of the eyepiece interface can prevent loss, suitable for viewing scenery, bright celestial bodies, nebulae, etc. 1 x Aspheric Eyepiece 2 x Lens Protection Dust Cover