Sleep, Relaxation, Wellness Sound Card Included! The Sound Oasis Sound Therapy System S-650 is a next generation sound conditioner that delivers an unmatched therapeutic sound experience. Featuring clinically proven sounds from world renowned doctors and the world�s finest authentic nature sounds, the S-650 helps you fall asleep easier and get higher quality sleep. It also creates a soothing atmosphere, blocks out irritating noises, helps circumvent tinnitus discomfort and enhances concentration so you feel more alert and comfortable throughout the day! The S-650 incorporates the world�s only "sound card" technology which enables you to change sound themes by simply inserting a new memory card containing 12 different sounds. The S-650 features; extra long, high fidelity sounds for exceptional sound realism, a backlit alarm clock allows you to wake to a buzzer or any sound, our patented Sleep Enhancement technology that slows down sound playback to lull you to sleep, a multi-position timer (with 4 selections: continuous, 30, 60, and 90 minutes), a unique "gradual off" volume reduction feature for a peaceful decrease in sound volume, a headphone/speaker pillow jack, a one-touch off/ resume button that stops the unit or repeats your last played sequence, and an omnidirectional reflective speaker that projects sound from the back of the unit for rich, deep sound. The S-650 can be powered by 4 "AA" batteries (not included) for portability or by the included AC adapter for convenient use at home or the office.