For centuries aromatics have been known as an effective way to promote feelings of relaxation and calm. Pur-Sleep's system of holistic, Essential Oils & Aromatics is designed specifically to compliment CPAP/BiPAP therapy. As you sleep Pur-Sleep's Passive Diffusion System lightly scents your therapy air you breathe with one of a variety of soothing, comforting fragrances to improve your overall mood as well as CPAP/BiPAP therapy comfort and compliance.