Ambi Pur 3volution plug-in diffuser with Odourclear technology cleans away tough lingering odours. Leaves a light fresh scent for up to 90 days (if used 12 hours a day at minimum setting). Doesn't mask but truly cleans away tough lingering odours. 3 scents alternate every 45 minutes so you always notice them. Adjustable scent intensity. Wide range of high quality fragrances.