Great product, well built and solid. The configuration file is excellent and allows you to set the fan speed for 55/60/65c to your choice with a minimum fan speed of 30%. I would have liked to be able to change the temperature set points as well but not a problem as I used the other option allowing me to set a constant 30% speed at a lower cpu temp. I prefer a constant temp where possible rather than having the fan switch on and off. Great utility as it allows you to see the cpu temp, RAM used, cpu utilisation for all cores, storage capacity, IP address and fan speed. With my Pi3 I had to space the fan hat slightly high off the IO pins as it sat at an angle due to the fan screw head touching the small CPU fan I had fitted. If you don't use a heatsink this shouldn't pose a problem