Windows 10's upcoming feature update, the Spring Creators Update codenamed 'Redstone 4', has reached the RTM milestone after it has been internally signed off at Microsoft last week. Build 17133 is the RTM candidate, which is expected to be seeded to Insiders this week followed by a staged rollout to production systems starting April 10.
https://www.notebookcheck.net/Microsoft-internally-signs-off-the-Windows-10-Redstone-4-Spring-Creators-Update-RTM-candidate.292644.0.html