Booster seat

A booster seat is a seat cushion that is used to elevate children in cars. Children have to use booster seats so that the seat belt fits better. 
In general most booster seats can be used for children who are between four and twelve years of age and between 40 and 59 inches (100–150 cm) tall. Children under 40 inches are usually too small to use booster seats and have to use a car seat (a child safety seat with an own seat belt system, used for children under the age of 4-6).
Many countries have laws that require the use of booster seats. In the United States of America children under 57 inches (145 cm) and younger than 9 years old have to use a booster seat. Many European countries require a booster seat until the child is either twelve years old or 59 inches tall. There are some exceptions. In the United Kingdom for example children are allowed to ride without a booster seat when they are 53 inches tall and in Austria children who are not 59 inches tall have to use a booster seat until their 14th birthday. However booster seats are used to keep children safe, not because of a law. In general no child can ride safely in a car without booster seat when he is not 57 inches tall. It is proved that children under 57 inches who do not use a booster seat are more likely to suffer serious injuries or even death in the event of an accident.