[ friendly ]Automatic shutdown after 30 minutes [Compatibility]Fit most crib mobile hanger,crib mobile arm.2 AA batteries are required, not included. Colour:White Material:ABS Size:14 x 9 x 3.5CM Package Contents: 1 x musicbox Only the above package content, other 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. *Mode button: song switching function, a of 12 music, each button to play song; do not press the button music automatically play to song. [Compatibility]Fit most crib mobile hanger,crib mobile arm.2 AA batteries are required, not included. * switch on/off button: button for play/pause function, press the button to , and then press the button to stop playing; motor works synchronously with music: motor rotates when playing music, motor stops rotating when music is paused. [ friendly design]Automatic shutdown after 30 minutes *Volume button: these two buttons have the same function, a of high / medium / low 3 grades of volume , each press the button the volume will be cycled between the high / medium / low 3 grades to select.