Product review (5 stars): Happy With Purchase
I saw other reviews that said they received a different relay than what is pictured, so I purchased the relay directly from Amazon and received the Aprilaire unit shown.  If you look at the top right of this page you can order from Amazon under the Other Sellers on Amazon section.  At the time I ordered it was only 42 cents more to get the part from Amazon.

Installed the unit in five minutes and it works well.  As others have said, you can loop your common blower motor wire through the metal bracket twice or more if you have a low amp draw from your motor.  After wiring the relay make sure that the metal bracket doesnt touch any metal objects or it might interfere with the operation of the relay.