Product review (4 stars): did what it was advertised to do
I worry a bit about the design of the shut-off.  It's subject to damage if not handled and adjusted properly, but it seems to be a direct replacement for the unit that came with the humidifier, so I can't fault the person selling the replacement.

I used this part to replace the existing/failed part and the humidifier is back up and running properly.

Aside  -  if you have any such humidifier and your water is hard, either get a water softener or you MUST clean the humidifier out every year.  The buildup of minerals will shock you.