Windows 10 build 17713 (rs prerelease)

Windows 10 build 17713 (rs prerelease) is an unleaked build of Windows 10 May 2019 Update. A .gif animation of this build can be found in the release announcement for October 2018 Update build 17713. It was used to demonstrate the Web Sign-in feature of the operating system.

Source

 * Official announcement for October 2018 Update build 17713