[Ten Smooth Sounds]: White noise machine with 10 smooth and natural sounds (white noise, ocean waves, birds, heartbeats, clocks, crickets, running water, and 3 lullabies) makes it easy for you to choose the right sound based on your preferences and needs to fall asleep. [Synchronization Design]: Sound machine for sleeping has synchronization design. It has three timer settings (15 mins/30 mins/60 mins) for your convenience to avoid forgetting to turn it off when you fall asleep, thus saving energy. [Aid to Sleep]: By masking noise and using peaceful, natural sounds to help relax your mind and body, the portable white noise machine makes it easier to sleep. It is suitable for home, office, dorm, nursery, and other environments. [Automatic Detection Function]: The intelligent white noise machine features automatic noise detection. When not in use, press and hold the Auto key for 2 seconds to enter noise detection mode for 10 seconds; cycle detection, with a detection distance of 6-10 meters. [Compact and Lightweight]: The noise machine is lightweight and compact, making it highly portable. You can easily carry it while traveling. It uses USB charging for added convenience.