Thank you for viewing. This is the SHOTEN MOUNT ADAPTER C.Y-N.Z. It's a mount adapter from Kani Koubou, used to mount Yashica/Contax lenses on Nikon Z mount cameras. I purchased it new from a camera store last year and used it a few times, but I'm selling my Contax lenses, so I no longer need it. I am now putting it up for sale. It was working properly. The items included are shown in the fourth photo. Please understand that this is a used item. Thank you.