Car seats have many parts and their names and functions may not be familiar to you. In addition, cars have parts that need to interact with car seats in specific ways to ensure the car seat is safely and securely installed. 

The photos and descriptions below outline a few of the main parts of cars and car seats that are important for keeping your child safe. Not all parts are listed here. Check in your car seat or booster seat instruction booklet and car owner’s manual for a full list and for more information on your car.

Parts of car seats

A green arrow points to the plastic or metal frame of the car seat.

Car seat shell

The plastic or metal frame of the car seat. The seat handle (if any) should be in the position required by the manufacturer.

Green arrows point to the harness slots on the frame of a car seat

Five-point harnesses and harness slots

The harness straps thread through harness slots on the frame of a car seat. All car seats have at least one set of harness slots. As your child grows, you may need to re-thread them through harness slots that are higher up on the car seat: the chest clip should be at armpit level. For your rear-facing child: make sure the harness straps are in the slot level with or just below your child’s shoulders. For your forward-facing child: make sure the harness straps are in the slot level with or just above your child’s shoulders. Check your car seat instruction booklet for how and when to re-thread the harness straps on your child’s car seat.

UAS connectors

UAS connectors (also called LATCH)

UAS stands for Universal Anchorage System. Car seats made after Sept. 1, 2002, come with UAS connectors. The connectors are two metal clips that are attached to each of a strap made from fabric “webbing”. The strap and connectors must be threaded through the right pathway on your child’s car seat and then buckled into UAS anchors in your car. You can use the UAS connectors or the car’s seatbelt to hold your child’s car seat in your car. Look in your car seat instruction booklet and your car owner’s manual for more information about the UAS.

A hand holds up the tether strap on a car seat

Tether strap

Forward-facing car seats use a tether strap to help keep the car seat in place. A tether strap also helps keep the top of the seat and the child’s head from moving too far forward in a crash or sudden stop. A tether strap is made from fabric “webbing”. One end is attached to the top of your child’s car seat. The other end has a hook on it so that it can be hooked to your car’s tether anchor.

Close-up of a metal “H-shaped” bar known as the locking clip

Locking clip

A locking clip is a metal “H-shaped” bar that can be attached to the seatbelt to keep the car’s seatbelt tight when installing a car seat. A locking clip comes with your car seat when you buy it. It is usually stored on the back of the car seat frame. You can also buy one in stores that sell car seats.

Check your car owner’s manual to find out if you need to use a locking clip to install a car seat using the seatbelt. Many seatbelts are designed so that you do not need to use a locking clip.

Parts of booster seats

Shoulder strap slot guide

A high-back booster seat with shoulder strap slots
Close-up of a plastic slot guide on a booster seat

Some booster seats have a plastic slot guide for the shoulder strap of a seat belt to fit through. The shoulder belt of your car’s seat belt can be threaded through a slot guide to help keep the shoulder strap off your child’s face and neck when she is riding in the booster seat. Check your booster seat instruction booklet for how to use the slot guide with your child’s booster seat.

UAS connectors (also called LATCH)

Green arrows point to the Universal Anchorage System (UAS) connectors on a booster seat

UAS stands for Universal Anchorage System. Car seats made after Sept. 1, 2002, come with UAS connectors. Right now, there is only one seat that uses UAS connectors to hold the booster seat into the car. The UAS connectors are connected to plastic bars on the booster seat. Look in your booster seat instruction booklet and your car owner’s manual for more information about the UAS.

Booster seat shell

It is the plastic or metal frame of the booster seat.

Parts of the car

Seatbelt

A seatbelt protects a person who is wearing it by holding them in place in the car. In a crash, the seatbelt keeps an adult or older child safe. Younger children, usually children under age nine, need a booster seat to make the seatbelt fit properly.

There are two main types of seatbelts: the lap-only belt and the lap and shoulder belt.

Lap-only belt

A lap-only belt has just one strap. It goes across the hips and buckles up. A lap-only belt protects the lower body, but does not protect the upper body (the chest, neck, and head). Some cars have lap-only belts in the back seat. Sometimes the middle seat in the back seat of a car has a lap-only belt.

Lap and shoulder belt

A lap and shoulder belt has two straps. The lap belt goes across the hips and the shoulder strap goes across the chest. A lap and shoulder belt protects the upper and lower body. All cars have lap and shoulder belts in the front seats. Most cars have lap and shoulder belts in at least one of the seats in the back seat of the car. 

UAS anchors

Green circles highlight the Universal Anchorage System (UAS) anchor bars on a car's seat

Cars made after Sept. 1, 2002, come with UAS anchors (also known as LATCH). Look in your car owner’s manual to see if you have UAS anchors in your car. They look like small metal bars and are attached to the car’s seat. Your car owner’s manual will also show where they are located in your car and how to use them safely with your child’s car seat. If your car does not have UAS connectors, use the car’s seatbelt to install your child’s car seat. 

Tether anchor

Demonstration of hooking to tether anchor

Cars made after Sept. 1, 2002 come with at least one tether anchor. Sometimes parents make the mistake of attaching a tether strap to places in the car that are not tether anchors (for example, cargo hooks, backs of other seats, door handles).

Look in your car owner’s manual to find the tether anchor in your car. If your car does not have a tether anchor, take it to a dealership to have one put in. Do not try to install one yourself. The dealer will know the best place to install a tether strap.

Top