Acoustic guitar humidifier that works for guitars without round sound holes?

[Stratguy]

The D'Addario ones don't go into a soundhole. You just put them in the case.

Actually, 2 humidipacks go into the sound hole, and 1 humidipack goes in the case under the headstock.

 

[Paully]

I think the one you ordered (Humitron) will fit your needs.
There's a very similar unit named "Dampit" that
I use, works like a charm.