There are three types of car seats you can put your children in: infant car seat [bucket seats], convertible car seats [infant to 35-45 check manual], and booster seats [with a full back or just the seat itself.] Today I will talk about Infant Car Seats.
'Infant carrier' means a restraint system intended to seat/lay a child in a rearward-facing semi-crescent position. This design distributes the restraining forces over the child's head and body, excluding its limbs, in the event of the front collision.
For young infants, the seat used is an infant carrier with the weight recommendations of 5-20 lbs. Most infant seats made in the US can now be used up to at least 22 lb and 29 inches, with some going up to 35 lbs. We use a Chicco Keyfit 30 which can go up to 30 lbs and 29 inches tall.
Infant carriers are often also called "Bucket Seats" as they resemble a bucket with a handle. Some [not all] seats can be used with the base, or just a carrier strapped in alone. Some seats do not have bases. Ours came with a base. We use the base in our main vehicle, but when I use my father's truck I would strap it in with a seat belt only.
Infant carriers are mounted rear-facing and are designed to "cocoon" against the back of the vehicle seat in the event of a collision. The impact being absorbed in the outer shell of the restraint not the child. Rear-facing seats are deemed the safest, and in the US children must remain in this position until at they are least 1 year of age and at least 20 pounds.
Although some parents are eager to switch to a forward-facing child seat because it seems more "grown up," various countries and car seat manufacturers recommend that children continue to use a rear-facing child seat for as long as physically possible. We personally practice forward facing until age two. Safety is key here!
Position: Sitting, rear facing, no airbag.
Recommended weight: Birth to 29 lbs.
Approximate age: Birth to 15 months.
On average, most seats expire 6 years from the date of manufacture, although this can vary by manufacturer.
Like motorcycle helmets, child restraints are tested for use in just one crash event. This means that if the restraint is compromised in any way [with or without the child in it], owners are strongly suggested to replace it. This is due to the uncertainty with how a compromised child restraint will perform in subsequent crashes.
The purchase of a used seat is not recommended. Due to the aforementioned concerns regarding expiry dates, crash testing, and recalls. It's worth spending the money on our children's safety and well being than getting a car seat for a cheap price. Children traveling by plane are safer in a child safety seat than in a parent's arms. The FAA and the AAP recommends that all children under 40 lb use a child safety seat on a plane. Booster seats cannot be used on airplanes because they don't have shoulder belts.