Product review (3 stars): This part is Not Needed.
Really just a cheaply made $2buck part.  WAY over priced.  BUT, think about it!  I did, but only after I spent $12.  One does not really need this part at all.  It is just to avoid spills until the container is inserted fully into the humidifier.  Once in place, the plunger on the part is depressed and water is released until the unit's float mechanism stops the flow at the proper level, part or no part.  After filling the container bottle, carry it discharge hole up until reaching your unit.  Then just turn it right side up and install in its place.  Water will start to flow immediately as you turn it upright, but that is of no consequence.  Everything in the unit is wet anyway.  I did this successfully until my part arrived.