ultrahumanite

There is approximately 7mm space above the 40.5mm and if you remove the small angle iron at 150mm, you can place longer (even 300mm Flex ATX PSU). The PSU needs some space for ventilation. However, I am not aware of any fanless Flex ATX PSU which would be powerful enough. If there was a hole at the bottom and 8cm slim PSU intake air/exhaust fan, that would be ideal.

Okay, thanks for the info. I was hoping to use a 500w PSU, 200x82x53mm dimensions, I guess it won't fit.

@goalque I was wondering if you'd be willing to answer a question about the dimensions of the Netstor NA211TB enclosure? From reading your post I gather that the enclosure comes with a standard Flex ATX PSU size 150mm x 81.5mm x 40.5mm. It looks like a longer (over 150mm) PSU would fit the case without any issues. It also seems like there is some room above the stock PSU so a PSU taller than 40.5mm should fit inside the case in place of the stock unit, would you mind measuring how much space is left above the 40.5mm? Thanks in advance.