Sport version and a bit lighter than the 150-600 sport.
https://nikonrumors.com/2018/09/21/specifications-of-the-upcoming-sigma-lenses-28mm-f-1-4-40mm-f-1-4-70-200mm-f-2-8-and-60-600mm-f-4-5-6-3.aspx/
https://nikonrumors.com/2018/09/21/specifications-of-the-upcoming-sigma-lenses-28mm-f-1-4-40mm-f-1-4-70-200mm-f-2-8-and-60-600mm-f-4-5-6-3.aspx/