I got the first one, with my first WF020 fountain, 16 month ago, in March 2022. I already had a fountain but I wanted a second water supply for my two cats and my big dog.
It's just a must have accessory. With this, the fountain only works very few hours a day, only when needed instead of 24h/24. So I'm saving water (less evaporation), saving electricity and saving pump lifetime.
I'm so happy with it that I bought a second fountain with that motion sensor in November 2022 to replace my still working old fountain.