RTIC went and re-designed their 30oz tumbler, and the old handles don't fit on the new mugs. My guess is they did it to make people buy new accessories. Maybe YETI did it first and they followed suit. I don't know if this will fit YETI Ozark or any of those other brands.
No clue why, but here is a re-design of my old two piece handle. It is a single piece print, but most people have printers big enough these days to handle it.
Read more about this design any my other work on my blog: https://kiltedcraftworks.com/2019/05/05/april-2019-prints