TLDR: this case will hold all Oakley X Metals models (incl larger ones like Romeo 1) and provides fantastic protection covering anything most people will ever need. There is nothing better available in the under $25 price range.
I was looking for a while for a reasonably priced true hard-shell case that could contain unusually wide glasses like the Oakley X Metals line. For those who don't know, most of the X Metal models have arms that stick out almost an extra 1" from each side when folded, making them unable to fit in most cases. This case is the perfect size for the larger X Metal frames including Romeo 1, X Squared, and XX. The smaller X Metal frames also fit and shouldn't slide around much if inside a microfiber bag.
To avoid any confusion, this is a "semi-rigid" case, NOT a true hard case along the lines of the Oakley carbon fiber or torpedo cases. I did originally set out seeking a true hard case, but after reading a thread on OakleyForum where this case was mentioned as the best lower priced option, I tried it and have not been disappointed. It provides plenty of protection for X Metals in all but the most extreme use cases. There are sturdier cases on the market, but they cost a lot more than the $22 for this one at the time of writing.
Bottom line: get this case for your X Metals. I'm planning to order 8-10 more in addition to the one I got to try.
-- OakleyForum member Jurist