1.the product has a total of 5 buttons, a switch button (including play / pause function), a timing button, a light button, a previous one (including sound reduction function), a next (including sound plus function) .2. the light button can work independently, can work without booting. 3.long press 0.5 seconds to open the key, short press for playback pause, play a music after boot, the music is made to cycle. Press the top and bottom to switch, long press to increase or decrease the volume, play with memory after booting, which music also has memory, the next time you turn on the phone automatically play the last time you turn off the music. 4.press the light button, divided into 6 cycles, from 10 minutes to 0 for a cycle, 10 minutes to start counting down, 10 minutes to start breathing rhythm gradually slow down. The light is bright for inhalation, the light is weak and exhaled, and the breathing is guided. This function is automatically turned off for 1 hour. In the case of no timing function, if the timing function is turned on, the time is set. 5. the time is divided into 15 minutes (bright red LED) 30 minutes (bright green LED) 60 minutes (bright blue LED) short press switch, the fourth turn off timing. They are indicated by LED lights respectively. 6.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).7. It features a light display and according to the light, you can adjust the breathing in 10 minutes to make your body relaxed.8.It features built-in lithium battery and USB charging. It can be used continuously for 36h for a full charge. Product information: Name:Sleep Machine White Noise Machine Sleep Sound Machine For Sleeping & Relaxation for Baby Adult Office Travel. Built in USB Timer Product parameters: color:white Material: ABS+PC+silicone+electronic components Size: about 80*80*33mm/3.15*3.151.30 inch Input volt