The hardness of the mattress varies from person to person. "Sleeping on a hard bed and using a hard mattress" has always been regarded as a good habit for people to protect their backs and keep fit. Especially for infants and young children who are in the growth and development period, such as sleeping on a hard mattress, it will cause skeletal dysplasia and even leave the hidden danger of "scoliosis". Children should consider two factors when choosing children's ...