Feature: 1. BUILT IN 20 SOUND SOURCES: Built in 20 kinds of sound sources, no need to connect to download, so you can enjoy diverse music choices anytime and anywhere. Highly reproducible sound quality, allowing you to enjoy a real music experience. 2. 1000MAH CAPACITY LITHIUM BATTERY: White noise machine is powered by a built in 1000mAh lithium battery, which is safety certified in accordance with certificate 62133, and takes only 3 hours to fully charge, with a working time of up to 9‑14 hours. 3. TIMER FUNCTION: Portable white noise machine supports timer function, you can choose 4 levels of timer settings, including 30 minutes, 60 minutes, 90 minutes and off, to meet your personalized needs. 4. ONE BUTTON POWER ON: Portable white noise sound machine supports one touch power on, no need for WiFi distribution. With a maximum usage range of about 20m / 65.6ft, enjoy music and move freely at the same time. 5. LOW BATTERY ALARM FUNCTION: Portable sound machine has a low battery alarm function, when the battery is low, it will emit a drip drip drip alarm, reminding you to recharge in time, and always keep the energy of the sound machine. Specification: Item Type: White Noise Machine Material: ABS Battery Type: Lithium Battery 1000mAh (Shipped With Built In Battery). Package List: 1 x White Noise Machine1 x Charging Cable1 x Instruction Manual