Sound oasis sound cards are the world"s only memory cards that allow sound machine owners to expand their collection of available sounds and music. By simply inserting the patent pending sound card, users can explore different parts of the world and experience a wide range of sound therapy. Each sc-300 series sound card contains our next generation playback technology for the clearest, most realistic sound quality available. The sleep sounds for baby sound card provides the ultimate selection of sounds proven to help babies and children of all ages to sleep. It incorporates seven authentic digital recordings of nature recorded in the wild by the world"s most foremost nature recorder, four sounds developed by world leading doctors in sleep and relaxation and one mechanical sound: white noise, ocean surf gentle rain, summer night, dolphins, prenatal, heartbeat, womb, lullaby, car ride, lullaby2, woodlands. Works with the sound oasis s-650-01 and s-650-02 sound sleep therapy systems.