Our sound machine has 6 sound groups, each with 5 categories of sound scenes that can be switched, providing free regulation of 30-level volume levels. The noise has 30 high-fidelity soothing sounds such as white noise, pink noise, brown noise, rain, running water, fan, tires, hypnosis, fire, waves, birdsong. They are perfect for birthday, Thanksgiving, Halloween, Christmas and other holiday gifts for family, children or friends. 3 Timer and Memory Functions: STYFSCP white noise can be set for continuous playback all night or a 30, 60-minute auto-off timer, which you can set according to your needs. When the timer goes off, the sound will gradually fade out and then turn off. In addition, the noise machine has a memory function and a headphone jack that automatically restores the volume, sound, and timer settings from the last time it was turned off, so you don't need to readjust them. USB Adapters and Portable: The speaker is equipped with a 5V/1A power adapter and a 1.5m USB power