Dohm-DS - the Official Sound Conditioner of the National Sleep Foundation.;Two speeds - dual speed motor, unique asymmetrical fan, and acoustic housing create the soothing sound of rushing air, the Marpac Signature Sound, without the disturbance of actual moving air.;Customized sound - acoustic housing and dual speed fan allow for fully adjustable tone and volume control for a personalized sound environment.;Voltage - 120 V, for domestic use only.;Guarantee - backed by a one-year limited factory warranty and the always exceptional Marpac customer service promise.