As part of an update released yesterday for those on the Fast Ring, Microsoft has now released the latest Windows 10 Technical Preview on the Slow Ring as well as ISO images. The ISO images are built on Build 10041 which the Fast Ring received last week. Microsoft had said that it would be releasing the ISO images when they released the latest build to the Slow Ring.
Remember that in order to get the ISO images or the Windows 10 Technical Preview in general you must be a member of the Windows Insider program which is free to join. As I have posted many times, the build is still very much in beta so unless you absolutely need to download it, wait until it is released to the public (for free) this summer.