Aromatherapy Diffuser by Guardian Technologies. Bring the luxury of a spa visit home! The PureGuardian SpaUltrasonic Aromatherapy Diffuser delivers a fine, ultra-quick mist and fragrant vapour with the addition of your favorite essential oil. Enjoy simple touch controls and automatic shut-off when empty. Small, lightweight, and portable, its perfect for the bedroom, office, dorm and hotel rooms.