Doesn't work.
I've spent money that I could have used for other things like food for my cats, instead I bought two of these Diffusers because we have a new cat. Both diffusers were on all day and night for a week and nothing changed between all four of my cats. My oldest cat attacked the newcomer right in front of one of the diffusers! I followed the instructions and now feel completely conned! Don't waste your money on this, in my experience it does not work.