Samyo Baby Crib Baby Bedding Battery-operated Musical Mobile Plays Twelve Tunes (Without Arm) Plays Twelve Beautiful Tunes(not the entire song) with the mobile slowly rotating Can be installed on baby's bed, Just the mobile without arm Easy to operate. The red button is for on/off,the green button is for next song Battery-operated by 2 AA batteries(Batteries not included). Material: ABS without pollution. Color: White Note: This Music Mobile could NOT adjust the volume. If you feel it's too loud, please put a little tape over the speaker to tone it down a bit.