1、6mm Focal Length: This lens has 6mm focal length, 25in joint diameter, which is suitable for 25in astronomical telescope. 2、66 Degree Wide Angle: This astronomical telescope wide angle eyepiece has a 66 degree field of view, 5 elements in 3 groups. 3、Optical Glass Lens: The lens adopts multi layer high definition broadband green film optical glass lens, chromaticity adjustment, which provides high permeability to ensure clear and has clear scenery. 4、Fully Coated Glass: The fully coated glass with excellent image contrast and light transmission with high brightness, large field of view that can keep your eyes in a comfortable state. 5、Applicable Scene: The lens is suitable for viewing scenery, bright celestial observation, nebula, etc., and it is also Halloween birthday Christmas gift for family and friends.