I have had a few power supplies with 2 pin connector. The purpose was to be plugged in to a regular 3 pin fan connector on the motherboard. Normally, the 3 pins are power, ground, and speed sense. The 2 pins coming from the supply is simply the sense and a ground, leaving the power on the motherboard's connector empty. This allows you to monitor the fans speed using the BIOS or other software.

If you go to this webpage here (overclockersonline), they review this PSU. Please scroll down to the 5th photo. This is a drive bay style fan controller, and it's got a 2 pin plug on the end of it.

If you continue to scroll down this webpage and look at the 10th photo, you can see the 2 pin cable (red and black, near left middle edge of photo) which you use to connect to this drive bay style fan controller. You can also see the 3 pin (but only 2 wire, yellow and black, middle of photo) mobo PSU fan connector cable.

On the photos it looks like the "fan controller" is simply a variable resistor. You can get these at any electronics parts store.

Strange product...

It has 2 fans and the website does list different RPMs depending on temps...

It also has a bay and a rear bracket fan controller? One for each fan maybe?

What if you set the fan to min and temp is 90c? Would the temp controller override the fan controller?

Weird design for sure 🤣

Strange product, yes perhaps. Good PSU, yes. I am going to investigate the variable resistor! 😀 Thanks a lot for all the input people.