Positively-charged molecules of ZERO surround and attach to the negatively-charged malodor molecules, pulling them out of the air and leaving behind just the right amount of essential oil. ZERO is essentially fragrance free. Sub-micron technology (particles size typically below 1 micron). Organic and environmentally friendly. Comes with a fully recyclable retaining clip. Fits into the Vectair V-Air® Solid Dispensers and most competing dispensers.