This is a great, reliable, simple thermal fan controller. Just plug the fans and the power cord in, point the probe in the direction of your hottest gear. If you only want the fans to run when your AVR is on, you can do that too, with the sensor bypass switch. Very well thought out. The green power light is a bit bright, so you might find yourself putting some electric trap over it.
Needed a thermostat for the built-in entertainment system, used to run the fans full speed all the time but not a fan of the noise. Works perfectly, easy to install, worked with my existing power supply and fans I had bought previously.