Feature:1. 1.25 Inch: 2x magnification with 1.25 inch interface increases the magnification of any 1.25 inch eyepiece and also provides comfortable viewing.2. 2X Magnification: Provides more magnification without reducing the exit aperture on the eyepiece and maintains a comfortable viewing field. Let you better explore the astronomical landscape.3. Optical Glass: The lens adopts optical glass, FMC green coating. The edge of the lens is fully coated with black matte paint, which can be matte and has a good light transmission performance and clear image.4. External Thread Specification: M42x0.75mm, suitable for connecting to a camera mount with T2 photography thread, if you don't need an adapter ring, you can also use a M35x1mm thread mount.5. Internal Thread Specification: M28.6x0.6mm, suitable for connecting 1.25in astronomical telescope filter and astronomical telescope eyepiece accessories.Specification:Item Type: Magnification Barlow LensMaterial: Aluminum alloy, optical glassGross Weight: 105g / 3.7ozMagnification: 2XInterface Size: 1.25 inches /31.7mmExternal Thread Specification: M42x0.75mmInternal Thread Specification: M28.6x0.6mmLens Coating: FMC Green CoatingMatting Treatment: The edge of the lens is fully coated with black matting paint.Package List:1 x Magnification Barlow Lens2 x Dust Cover