Colorado, designed a forward-facing seat with a metal frame to protect the child. Seat belts for adults were not standard equipment in automobiles until the 1960s. Child safety seats first became available in the late 1960s, but few parents used them. Classifications There are several types of car seats, which vary in the position of the child and size of the seat. The United Nations European Regional standard ECE R44/04 categorizes these into 4 groups: 0–3. Many car seats combine the larger groups 1, 2 and 3. Some new car models includes stock restraint seats by default. Group 0 Group 0 baby seats, or infant carriers, keep the baby locked up in a rear-facing position and are secured in place by a standard adult seat belt and/or an ISOFIX fitting. Group 0 carrycots hold the baby lying on its back. Carrycots are secured by both seat belts in the rear seat of the car. Both types have handles to allow them to be easily moved into and out of the car. Position: Lying (in carrycots), rear-facing (in infant carriers), no airbags (with the exception of curtain airbags). Recommended weight: Birth to Approximate age: Birth to 15 month Fastened carrycots Carrycots or infant car beds are used for children that cannot sit in a regular baby seat, such as premature infants or infants that suffer from apnea. A carrycot is a restraint system intended to accommodate and restrain the child in a supine or prone position with the child's spine perpendicular to the median longitudinal plane of the vehicle. Carrycots are designed to distribute the restraining forces over the child's head and body, excluding its limbs, in the event of a big crash. It must be put on the rear seat of the car. Some models can be changed to face forward after the baby has reached the weight limit which is normally about . Carrycots generally include a stomach belt and a connection to the (three points) safety belt. Infant carriers Infant carrier means a restraint system intended to accommodate the child in a rearward-facing semi-recumbent position. This design distributes the restraining forces over the child's head and body, excluding its limbs, in the event of the frontal collision. For young infants, the seat used is an infant carrier with typical weight recommendations of 5-20 lb. Most infant seats made in the US can now be used up to at