Fits my Klippe perfectly, I'm sure it'll fit a 65% fine. Wish there was a LITTLE more cable space, but that's not even really physically possible with the design.
I originally got this for my womier k66 and now use it for my Nuphy Halo65 with no issues. It's snug, but in a secure way, and I'm able to fit a cable and a microsoft arc mouse in the interior pocket.
I have a custom build 60% keyboard and this fitted perfectly inside. I think the build quality is really good and helps protect my keyboard when I’m on the go.