1、For Observation: Widely used for astronomical observation of celestial bodies such as the lunar surface, planets, nebulae, star clusters, etc. 2、Standard Design: Comes with standard 25in interface, that is, 37mm interface, so this eyepiece will match with all astronomical telescopes. 3、Premium Coating: Good optical glass lens is fully coated with multiple layer FMC film, which will offer high brightness and definition for you. 4、With 10mm Focus: The astronomical telescope eyepiece with 10mm focal length ensures wide viewing range, making your observation comfortable. 5、Great Materials: Fully metal body of aluminum alloy together with a light weight and a compact size will largely improve overall durability. 1 x Astronomical Telescope Eyepiece1 x Storage Box Item Type: Astronomical Telescope EyepieceMaterial: Aluminum Alloy, Optical Glass LensFocal Length: Approx. 10mm / 0.39inInterface size: Approx. 31.7mm / 1.25in