Scratch Proof: A metal gasket is built into the interface of diagonal adapter prism to prevent the prism from being scratched by screws during use. Clear Imaging: Adopting 99% high reflective dielectric film, diagonal adapter prism has excellent optical performance, high reflectivity, high transmittance, bright and clear imaging. Internal Thread: The diagonal adapter prism interface has internal thread that can be used to mount filters, or with your other telescope accessories. Real a practical and convenient equipment. Main Function: Suitable for astronomical telescopes with 2 inch interface, for viewing landscapes and astronomical observations, such as the Moon, planets, nebulae, star clusters, diffuse nebulae and other space objects. 2 Inch to 1.25 Inch Adapter: The diagonal adapter prism interface comes with a 2 inch to 1.25 inch adapter, allowing you to freely switch between 2 inch and 1.25 inch eyepieces.