What they have done to create this, is take their M70/80/90Q series platform, turn the motherboard upside down, add an internal PSU and create a shell with the dimensions exactly the same as the 1L chassis from the ThinkCentre series I mention above. While quite a smart move cost-wise, I think the serviceability of this PC will suffer - the RAM and M.2 SSDs are now mounted under the top cover, which is not removable, so you need to take the motherboard out to reach those.