Good case, but hardly fits HifiMan i400 as it is a bit shallow and squeezes the headphones a bit.
I'd recommend this case but I'm not personally very happy with it. It has a strong chemical smell inside, this thing is really big. It fits my HEX V2 but with so much wasted space. It's also heavy. It is big enough for the HIFIMAN HE1000 and HEX, Ananda, Arya etc. but it's not ideal. When you take out the foam pieces to make it fit, there is no front and back padding. The foam is rigid which kind of digs into the headphone ear pads. Not ideal, but with so few options, it'd work.