Thank you for viewing. This is the VALTROX EF-R2 mount adapter with control ring. It's an EOS EF to EOS R (RF) conversion adapter. There is a problem with the following: Although it has a control ring, the internal teeth are broken, and it only responds in a small section. The mount ring function works without issue. - Brand: VALTROX - Model: EF-R2 - Type: Mount Adapter - Color: Black - Features: For lens attachment EF-RF conversion