Microsoft released an RTM build to Windows Insiders on both the fast and slow ring.
As you may or may not know RTM (Release To Manufacturers) build is usually the final build that Microsoft sends to OEMs to incorporate into their devices they will sell running Windows 10.
This latest build is probably one of the last builds (if not the last) we will get before it goes live on July 29th to everyone. It was even delivered through Microsoft's Windows update servers. So you should get this update automatically.
This build also removes the desktop watermark that shows what build you are running. Though you can see see what version you are running by using the "winver" search keyword in the search box.
In this build, Microsoft Edge has been greatly improved, making in faster than Chrome and Safari.
Also, Microsoft Office apps have been stripped of their "preview" tag.
You can read more about this RTM build on Windows Blog