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, 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 . 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 ( LED) short press switch, the fourth turn off timing. They are indicated by LED lights respectively. 6.Automatic shutdown timer: This 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 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 voltage: DC5V Working voltage: 4.2v Charging current: 1A Power: 1W Battery capacity: 1200MA Charging : USB Charging time: 1.5h Use time: 36h Features: 1.9 kinds of smooth and : It features white noise, wave sound, birdsong, waterfall, cricket sound, bicker and 3 lullabies, so that you can choose sounds according to your preferences and needs to create a quiet environment to fall asleep quickly and rest completely . 2.Portable design: Only 8*8*3.3cm. It takes up a small space on the bedside table and can be easily put into your bag or suitcase, making it the perfect travel . 3.Not just for sleep: our white noise sound machine not only masks noise, improves sleep quality, but also is suitable for use , in the office, in a dorm, in a baby nursery or anywhere you want. Product List: 1 *Sleep instrument machine 1 * USB line 1 *Instruction manual Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.