EF-EOS R is the lens adapter for Canon EF/EF-S lenses to Canon EOS R series cameras. It has metal electrical contact pins which is auto focus.
The control loop is integrated on the adapter ring which can achieve the same operational feel as the RF lens control ring when connect to lens
By adapter mounting it can achieve functions of EXIF signal transmission,auto focus and aperture adjustment,etc. Detachable tripod adapter provides support for longer Canon lenses.