The adapter allows you to use all Canon EF and EF-S lenses on the new Canon RF mount cameras. It has a control ring that can be programmed for, for example, stepless exposure compensation.

The Canon EF - EOS R Mount Adapter allows you to use all Canon EF and EF-S lenses on the new Canon RF mount cameras ( e.g. Canon EOS R body ). The body will automatically go into 1.6x crop factor mode when using a Canon EF-S lens.
This EF-RF adapter has a control ring that works in the same way as the Control Ring on Canon RF lenses. This means you get a convenient and customizable control ring for all EF lenses. The ring can be programmed to perform functions such as exposure compensation, aperture adjustment, or changing the camera's ISO sensitivity.
This adapter does not contain any lens elements that affect image quality, the aperture and focal length remain exactly the same. All Canon lens features such as autofocus, aperture control and image stabilization work through the adapter. The Canon EF-EOS R adapter is also weather-sealed and has a sealing ring on both sides, so weather resistance is maintained between the lens and the camera.
There is also a version of the adapter without an adjustment wheel and a version with an adjustable ND filter and a polarizing filter .
Sales package includes: Mount Adapter EF-EF-EOS R Control Ring Mount, Body Cap RF-3, Lens Dust Cap RF, User Manual and Protective Pouch