We have two models of Crystal AIre Purifiers in this collection. Both only use Crystal Aire Concentrates which are water based. We do sell a selection of different concentrates which are used in this machine. Namely Ocean Mist, Eucalyptus and Vanilla which are available in 200ml and a 3 X 30ml pack of all three. We also have Crystal Rain, Fields of Lavender and Wild Forest which come in 30ml size bottles.