White Noise Machine, Auto Shut-off Timing Sound Machine, Portable Sleep Aid Device With 10 Relaxing Nature Sounds [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 one sound based on your preferences and needs sound to fall asleep. [Synchronization Design]: Sound Machine for Sleeping has synchronization design. It has three timer settings (15mins/30mins/60mins) for your convenience to avoid forgetting to turn it off when you fall asleep, thus saving energy. [Aid to Sleep]: By hiding 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, etc. [Automatic detection function]: The intelligent white noise machine adopts the design of automatic noise detection. When not on, press and hold the Auto key for 2 seconds to enter noise detection for 10 seconds; cycle detection, the detection distance is 6-10m. [Compact and lightweight]: The baby noise machine is lightweight and compact, so it is very portable. You can easily carry it while traveling. It uses USB charging, which is convenient.