I have this model humidifer in two different versions.  One with a with the cap on the underbelly of the tank, the other on the tip where the water comes out of the tank.  Well, I needed a replacement tank for the humidifier with the tip-end release and got the underbelly one, and since it didn't come with a cap I can't use it, so I just wasted money!!  Kaz you really should sell these with the cap!!!!

I threw out our original tank that cracked - not knowing I would need to keep the cap!  I can't imagine why they don't include the cap with this!  They should either include the cap, or sell the humidifier with a big note printed across it warning the customer to keep the cap in the event they need to order a replacement tank.  Ridiculous!

They sell replacement tanks for models that have changed the design and won't work even though the model number is the same. They don't tell you this or even offer the option to get the right part. Its like ordering from a back alley chinese shop cart. Spend a little more money and buy from a more organized company. They told me to call back during the week, some people still work and can only deal with BS on the weekends.