Diffusor Tranquility Model

 
This is the newest model, small and quiet. Suited for treatment rooms or offices where noise is a concern. Best for rooms less than 500 square feet. No on/off switch, just plugged in or unplugged.
This is the model I use in the house. I've replaced the glass twice in the 15+ years I've had it. It gets a lot of use here, I've loaned it too. I treated myself and my family to this expensive model at the beginning of some flu season and it has served us well all this time.