On/Off Button: Play/pause function. Press once to play, press again to stop; the motor synchronizes with the music: the motor rotates when music plays, stops when paused. Mode Button: Song selection function. 12 songs total; each press plays the next song; if you don't press, it automatically plays the next song. Volume Control Buttons: These two buttons have the same function. Three volume levels (high/medium/low); each press cycles through the levels. [Adjustable Volume] Unlike traditional music boxes with only 3 volume levels, this crib mobile motor offers stepless volume control (0-100), allowing you to choose the perfect volume. [Soothing Music] 12 lullabies, selectable at will. Previous/Next song options. Choose your baby's favorite music for a peaceful sleep. [User-Friendly Design] Automatic shutoff after 30 minutes. [Compatibility] Fits most crib mobile hangers and arms. Requires 2 AA batteries (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 to differ slightly from the real thing. The allowable measurement error is +/- 1-3 cm.