Mount adapter that allows EF lenses to be connected to EOS R bodies. I purchased this when I switched to the R series, but I only used it a couple of times initially and then switched to RF lenses, so I no longer need it. If you are looking for one or want to get one cheaply, please consider purchasing. - Brand: Canon - Model: Mount Adapter EF-EOS R - Features: Allows EF lenses to be attached to EOS R bodies - Connection Type: Mount Adapter Thank you for looking.