Thank you for viewing. This is a URTH lens mount adapter. It's an adapter for mounting Contax/Yashica (C/Y) lenses on Canon RF mount cameras. It can be used with lenses like the Contax Planar 50mm f/1.4, known as the king of standard lenses. Made by URTH, as expected (currently 11,900 yen on Amazon), it fits perfectly. I think it's a beautiful product with almost no signs of use, but please refrain from purchasing if you are concerned, as it is a used item. ■Other Notes■ Please purchase only if you understand that it is stored at a private residence. Please understand that it is a used item and that, to prevent swapping, we will not accept returns or exchanges (NCNR). We will ship within 2-3 days, but please note that it will take some time to arrive as we are located in Okinawa.