Nut Size That Holds the Apex Processor Power Supply

Issue

I need to replace the power supply in my Apex Processor, but I cannot find the correct size nut driver for the strap that holds the power supply in place.

Pictured: two of the four nuts in question.

Solution

These are M3 5.5mm nyloc nuts (ETC P/N HWM1813) and will require a 5.5mm nut driver.  Note that you will also need to remove 4 Phillips head screws (ETC P/N HWM10071) from the underside of the power supply as well.