You’re welcome.
I don’t recall and am not at home, if it’s wired to only one of the fans or both. It’s definitely hard wired to the part fan speed though.
For this reason, I made an analog voltage divider with a heavy duty potentiometer and switch to be able to slow it down or turn it off when desired.
Henry on the Facebook group also made a PWM reducer he was selling little kits for at cost.