This is the SHOTEN Koubou UMS series. This is a mount adapter that allows you to use Mamiya 645 lenses on Fujifilm GFX cameras. There are no deformations and there are no problems with the operation, but there is one scratch (see photo 4). The following is the manufacturer's description: Expandable Mount Adapter | Product By SHOTEN The SHOTEN UMS series has a two-part structure, and is a product with a new concept that allows you to replace the body-side mount parts. A new concept with a two-part structure Further expandability. Freedom to choose a camera body By replacing the mount parts on the adapter body side, it can be attached to cameras with different mounts. When you buy a new camera or want to use it with cameras from various manufacturers, you don't need to prepare a new mount adapter, and you can effectively utilize your existing equipment. Further expandability. Freedom to choose a camera body 9 types of dedicated mount parts for the body side Sony E / Nikon Z / Canon RF / Fujifilm G / L / Leica M / Fujifilm X / Micro Four Thirds / Hasselblad X (*Replacement parts are sold separately) Features By replacing the mount parts, it can be attached to mirrorless cameras from each manufacturer. The intermediate mount (U mount) part that connects the mount parts can be connected with high rigidity without any play. The inside of the adapter is painted with a matte finish to significantly suppress internal reflections.