On/Off Button: Play/pause function button, press the button to play, and then press the button to stop playing; the motor runs synchronously with the music: the motor rotates when music is playing, the motor stops rotating when music is paused. Mode Button: Song switching function, one of 12 songs, each button to play the song; do not press the button music automatically plays to the song. Volume Button: These two buttons have the same function, one of high/medium/low 3 volume levels, each press of the button the volume switches between the high/middle/low 3 levels to choose. [Arbitrary Volume] The baby music box has 3 levels of volume only. The crib mobile motor uses stepless volume, you can set the most suitable volume from 0 to 100. Say goodbye to the mobile music box. [Soft Music] 12 lullabies, which can be switched at will. Last, one. Your baby's favorite music and fall asleep quickly. [Baby 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 3.5CM Package Contents: 1 x Music Box Only the above package content, other products are not included. 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.