Product review (4 stars): The Valve Words Perfectly But Needed Screws
I installed the valve myself. After I mounted it on the humidifier, I set my thermostate for the valve to work, and it did perfectly.
 When I inspected the valve, I noticed that there wasn't any parts to attached the valve to the humidifier like screws or bolts.  When I took off the old valve, the nuts from the bolts fell into the humidifier.  I wasn't going to waste my time opening the humidifier and searching for the nuts.  Instead, I got the right size self-tapping screws from my inventory of screws and securely installed the valve with them.  The morale to this story is that the valve should have come with at least self-tapping screws.