Power On/Off Button: Play/pause function button, press the button to play, and then press the button to stop playing; the motor works synchronously with the music: the motor rotates when the music is playing, the motor stops rotating when the music is paused. Mode Button: Song switching function, a set of 12 pieces of music, each press of the button plays the next song; if you don't press the button, the music will automatically play to the next song. Volume Button: These two buttons have the same function, a set of high/medium/low 3 volume levels, each press of the button will switch the volume between the high/medium/low 3 levels to choose from. [Optional Volume] The music box only has 3 volume levels. The crib mobile motor has stepless volume, you can choose the most suitable volume from 0 to 100. Say goodbye to the fixed volume of the music box. [Soft Music] 12 lullabies, which can be switched at will. Play the last one, or the next one. Choose your baby's favorite music and fall asleep quickly. [Child-Friendly Design] Automatic shutdown after 30 minutes. [Compatibility] Fits most crib mobile hangers, crib mobile arms. 2 AA batteries required, not included. Color: White Material: ABS Size: 14 x 9 x 3.5 cm Package Contents: 1 x Music Box Note: Light reflection 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.