18 sounds: 3 fan, brown noise, pink noise, white noise, ocean, rain, brook, summer night, frogs, bird, hairdryer, crowd, fireplace, 2 flute and wind chimes. Leave on all night or set a timer for 30, 60 or 120 minutes. Recalls last sound and volume setting. Operates for 100 hours on 3 AA batteries (not included). Portable design that is perfect for home or travel. Mask background noises like barking dogs and snoring for improved sleep. Sounds mask private conversations making it perfect for office privacy.