Microsoft yesterday released Windows 10 Mobile 10136 to Windows Insiders. There are many subtle changes in the UI and UX to cover. In this build, Microsoft has added “3G only” to Mobile network speed settings. Earlier, you will be able select either 2G or 3G(4G if available). Microsoft is doing a lot of refinement to the UI/UX right now and you should see more of that work in the upcoming builds as well.