Features:1.9 kinds of smooth and natural sounds: It features white noise, wave sound, birdsong, waterfall, cricket sound, bicker and 3 lullabies, so that you can choose sounds according to your preferences and needs to create a quiet environment for you to fall asleep quickly and rest completely .2.Portable design: Only 883.3cm. It takes up a small space on the bedside table and can be easily put into your bag or suitcase, making it the perfect travel companion.3.Not just for sleep: our white noise sound machine not only masks noise, improves sleep quality, but also is suitable for use at home, in the office, in a dorm, in a baby nursery or anywhere you want.4.Automatic shutdown timer: This white noise machine can be played continuously non-stop all night or there is an auto-off timer to set for 15, 30 or 60 minutes to conserve energy.(light display).5. It features a light display and according to the light, you can adjust the breathing in 10 minutes to make your body relaxed.6.It features built-in lithium battery and USB charging. It can be used continuously for 36h for a full charge.Product parameters:Material: ABS+PC+silicone+electronic componentsSize: about 808033mm/3.153.151.30inInput voltage: DC5VWorking voltage: 4.2vCharging current: 1APower: 1WBattery capacity: 800MACharging method: USBCharging time: 1.5hUse time: 36hQuantity: 1 PcNote:1.Please allow 0.5-1cm error due to manual measurement. Please make sure you do not mind before you bid.2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you Product List:1Machine1USB1Instruction manual