The Nikon Rumors website has confirmed prior rumours about the launch of a new Nikon NIKKOR Z 600mm f/6.3 PF lens, likely to take place on or around October 10. It is said to be a relatively lightweight lens for wildlife and sports photography, featuring Nikon's Phase Fresnel lens element which improves sharpness while keeping size and weight down.https://www.notebookcheck.net/New-Nikon-NIKKOR-Z-600mm-f-6-3-PF-lens-with-Phase-Fresnel-element-rumoured-to-launch-this-week.758163.0.html
They have a 400mm pf as well in the z line