It's a monsterlabo case. They used to make a few models that were all heatsink so you didn't need fans. I think they might have gone out of business because their website has no stock left for ordering, etc. Too niche a product to sustain sales probably.

Edit. No website anymore either.

But here's the case I have. https://www.vortez.net/news_story/monsterlabo_the_first_chassis_now_available.html