Conair SU9 Serene Sounds Sound Therapy Machine with 6 Sounds (Rain, Ocean waves, Heartbeat, Summer night, Forest, Babbling brook), Timer control to set for 15, 30, or 60 minutes (chosen time lights up), Easily change sounds with a single button, Off/On/volume control, Sound control button (chosen sound lights up), Operates on 3 AAA batteries (not included).