Nikon f or nikon z?

Here is what the site says about that.

From Nikon Z 40mm f/2: Nikon Z 40mm f/2: A prime lens by Nikon for Full frame cameras, 40mm f/2. Small, cheap and good: Nikon's everyday prime.

From Nikon Z 50mm f/1.4: Nikon Z 50mm f/1.4: A prime lens by Nikon for Full frame cameras, 50mm f/1.4.

Quoted from this site's pages.