Add more sounds to your Sound Oasis Sound Therapy System for added variety. Contains 6, authentic, digitally recorded sounds. Includes the following 6 sounds: Thunderstorm in the Wilderness; Loons on Wilderness Lake; Mountain Valley Windstorm; Forest Rain; Waterfall; Roaring Bonfire. Simply insert into the Sound Card slot on the Sound Oasis S-550-03 model. Does not fit other Sound Oasis models.