Microsoft recently announced a new build of Windows 10 Mobile for participants of the Fast Ring software beta tester program. The release comes just ahead of the Lumia 950 launch, which hits AT&T and Microsoft stores this Friday, November 20 in the United States. That suggests it’s the final “release to manufacturing” (RTM) build of the mobile operating system.

Folks in the Fast Ring of the Windows Insider program should find build 10586 of Windows 10 Mobile now. “This build has a lot of good bug fixes and general improvements for you to check out,” Microsoft corporate vice president of the engineering systems team Gabe Aul said.

The latest software should fix issues related to Start menu software corruption and storage settings, and the physical camera button should work on all devices now. Aul explained that apps should download more reliably and that Microsoft also “made improvements to the Messaging + Skype app.” Additionally, Aul said users should expect faster switching between applications.

Public users who are currently testing Windows 10 Mobile should be able to find build 10586 by searching for a system update from the settings menu now.