Product review (3 stars): Works . . . if you have an energy hog
As long as the device you are using draw a significant amount of power this works perfectly. I initially bought this for use with an ECM motor (low power draw) and there was not enough amperage used to trigger the relay; I found another way to address the need with a hardwired relay. Some months later I have an occasion to use this and it works perfectly with the higher current use.

For the the price I would probably simply install a hardwired relay.