Fotodiox Reverse Mount Adapter Ring is made of premium grade aluminum. The lens can be solidly mounted on the camera in reverse direction for incredible macro photography. The Macro Reverse Ring works with all Canon RF mount camera bodies. Any lens with a filter thread, not just Canon RF lenses, will fit on the thread side of the adapter (expandable with step-up or step-down rings as needed), enabling you to convert almost any lens into a macro lens at a fraction of the cost while maintaining its original optical quality. For example, you can fit a Nikon F lens with the right sized thread on a Canon RF mount camera. This means you can now get macro performance without needing to switch to a specialized lens and you will retain all the normal benefits of your optic when the macro function is not in use. Because no other optical components are added with this ring, the image preserves the original optical properties of the lens. This is an affordable and simple way to turn your existing lenses into an inexpensive macro lens.