I do never used, bought cheap on ebay. Can make at home easy. Do need air pump paid $9 for one at petsmart I think @Smart Red and @aftermidnight both have one
Wonderful for rooting cuttings, I used mine for rooting Michaelmas daisies and fuchsias, works like a charm. I just gave mine to DS2 as I don't have a need for it anymore but when I did it was well used. Cuttings root quickly using one of these.
I went to the plastic shop and had a clear dome lid made for mine to cut down on the evaporation. Mine is like the top one....