I think the Nikon module was announced a long ago, but still not available for the Sinar M.
How do you attach 35mm Nikon lenses to Sinar M?
The Nikon module for the M was short lived as I understand. I have seen several for sale years ago. Actually as I mentioned I have used 3 out of 4 the M not being one of them. Lovely system but way above my comfort level of price/value ratio.