Just days after its previous Windows 10 Insider Preview build to the Fast ring, Microsoft has released a new build for Skip Ahead users. That is, this new build is for Redstone 4, the version of Windows 10 that is expected in March 2018.

“Insiders who joined Skip Ahead will continue to receive builds from the RS_PRERELEASE branch which has transitioned to RS4 which is the release that will come after the Windows 10 Fall Creators Update (RS3),” Microsoft’s Dona Sarkar explains. “Insiders will notice that the build numbers have jumped ahead to 1635x.”

So this RS4 release is build 16353, whereas the prior Fast ring (RS3) release was build 16278. This is the first time that a Skip Ahead build has diverged from Fast ring. (Previously, users in both rings got the same builds.)

As you should expect, there are no major new features in the build. It’s just too early for Microsoft to start testing such things. But there are few small improvements. Action Center supports a two finger touch gesture that dismisses all notifications, for example. And Action Center has a few minor visual changes. The rest is just fixes.

More confusing is that you couldn’t actually jump ship to Skip Ahead right now even if you wanted to. Microsoft only temporarily opened up the Skip Ahead ring to a limited set of testers, and it’s currently full. But once the Windows 10 Fall Creators Update is complete, the Skip Ahead ring will “go away” and everyone in the Fast ring will be on RS4 builds.