Zhongyi Optics Lens Turbo II N/G-NZ Focal Reducer Adapter (Nikon F-mount (G-type compatible) lens → Nikon Z-mount conversion) This is a unique mount adapter that allows you to use F-mount lenses, such as old Nikkor lenses, with Z-mount cameras, and also allows you to use APS-C cameras without significantly increasing the focal length of the lens. It's the perfect solution for cameras like the Z fc and Z 50. I am selling it because it doesn't fit my needs. There are no noticeable scratches or other damage. It is in beautiful condition. This video explains how to use it: https://www.youtube.com/watch?v=-lqa-UZtYHI&t=77s