Deep aluminium cap for Nikon Z lens mount

The cap is machined of high quality aluminium alloy, and it has increased depth.

Why you may need it? There are 2 main reasons:

1. It is stronger than plastic caps.
2. It is deeper than generic caps. If you adapted a lens with short back focus to the Nikon Z mount, the rear element of the lens will protrude from the adapter, and generic cap will not fit. The cap has 15.5mm depth, and it will fit any adapted lens therefore.