This mobile activity center allows your baby to learn both walking and eating and will helps to prevent O type leg and exercise the strength of limbs. There are two heights available to adjust according your baby's age. The top steering wheel is rotatable with a horn. Push the bottom at two sides then you will hear lovely music. The volume is controllable to prevent hearing damage. In addition as it is certified by ASTM you may rest assured that all the materials are friendly to baby. If you are looking for a baby walker like this don't hesitate to buy it! --ASTM certified quality guarantees baby's safety and health --Height adjustable design fits baby in different ages and heights --Simulated sound effect and rotatable steering wheel --Adjustable volume protects children's hearing --Damping rear wheel prevents over speeding "driving" --6 antiskid devices avoid rolling over while sliding on slopes --Can be used both for walking learning and baby caring --Can be stored in narrow spaces with foldable design --Easy to clean up with cushion of detachable design