Anyone have a link to Sierra 10.12

Hi all -

Finally upgrading from 10.11.6 and of course 10.12 is elusive to find. Why is that? Every other 10.12 is avail - just not the first one .. can you help with a link?

Thanks!

Troy Christian

G5 Quad, 8GB RAM, FCP HD Suite 2 6.0.5, OSX 10.5.6
AJA LHe card