HIGH FIDELITY & LOOP-LESS 20 SOOTHING SOUNDS - white noise machine has 3 white noise, 3 fan sounds, 3 rainy sounds, 3 Sea Wave, 2 Lullabies, Water Stream, Campfire, Bird, Cricket, Tick-tock, Heartbeat. Select the perfect channel and get ready for your personalized sleep therapy!WARM NIGHT LIGHT GUARDS BABY SWEET DREAM- This sound machine features an optional night light that provides a good sense of safety and can lull babies into sleep naturally.AUTO-OFF TIMER OPINION- The sound machine allows you to setup optional 15, 30, and 60mins automatic shut-off timer without getting up to turn off this device or leave it playing all night.EASY USE & MEMORY FUNCTION - Whether you are taking nap, relaxation, meditation or concentration while studying or working, the sound machine remembers your last settings of the sound and volume level when you next turn it on.BATTERY OPERATED & PORTABLE- This white noise sound machine comes with a 1200hAm battery, which could use 30 hours after full charging. It is small and lightweight, portable for offcie and travel use. It easily fits into your purse, bag or suitcase, easy to carry with you wherever you go, you don't need to worry about sleeping in a strange environment any more.