... 4.Usage:baby learing 5.OEM/ODM Sound Board Book for Baby SpecificationInput Voltage4.5V(3pcs 1.5V batteries) ... 22cm W, 1.2cm HButton Qty6 buttons, customizedOperationPressing for soundAudio FormatMP3,WAVAudio Duration1-270s , even more if needed ... birds, vehicles, baby and songs.ComponentsPlastic shells, Printed cardboard, printed labels, PCB, IC, PET printed board, loudspeaker, batteries, wire ...