Email Sign Up
Safety Notices

Definitions and Glossary

Anti-Rebound Bar
Helps control rebound and decrease the possibility of head contact. Rebound is the “bounce” after initial impact has occurred.

anti-rebound bar

Automatic Restraint
Passive restraint that requires no action by the user; (e.g., shoulder or lap/shoulder belts that automatically wrap around the occupant; air bags).


Base (of a child seat)
The base of a child seat is the lower portion that rests on the vehicle seat.  A detachable base that comes with many infant seats is used to permit a fixed installation into the vehicle allowing the child seat to be taken in and out of the vehicle without having to do a new installation each time.

car seat base

Belt Path/Route
The manufacturer's required place where the safety belt passes around or through the child restraint.


Belt Webbing
A term used to refer to the vehicle seat belt material. Sometimes the straps on a child seat are referred to as “webbing” as well.


Booster Seat (Belt-Positioning Booster)
A type of child seat that does not use a five-point harness but simply boosts the child so that the vehicle seat belt is positioned correctly across the child’s hips and shoulder.  Booster seats rely on the vehicle seat belts to hold both the child and the booster seat in position.  The use of a booster seat depends on a child’s age, height, weight, and maturity.  Never use with a lap belt only across the child.

booster seat

The locking mechanism of the vehicle belt or child safety seat. The latchplate fits (clicks) into the buckle, which must have a red button.

car seat buckle

Car Seat
Common term for a specially designed device that secures a child in a motor vehicle, meets federal safety standards, and increases child safety in a crash.


Chest Clip
The chest clip is the device on the harness straps of the child safety seat used to position the straps properly on the child.

chest clip

Child Safety Seat/Child Restraint
A crash tested device that is specially designed to provide infant/child crash protection. A general term for all sorts of devices including those that are vests or car beds rather than seats.


Combination Child Seat
A type of forward facing child restraint that is used with an internal harness system to secure a child; with the removal of the internal harness, it is used as a belt-positioning booster (BPB) seat.

combination child seat

Compliance Tests
Rigorous crash and static testing done to assure that manufacturers meet required federal standards. Child restraint performance requirements have been established by the National Highway Traffic Safety Administration (NHTSA).


Convertible Car Seat
A child seat that "converts" from rear facing for infants and small toddlers to forward facing for older/larger children.

convertible car seat

Child Passenger Safety


Crumple Zone
The zone of a car that absorbs energy upon impact.  The purpose of a crumple zone is to increase the amount of time it takes the car to come to a complete stop in comparison to the object that the car hits.  Increasing the time that it takes for the car to come to a stop after hitting an object allows the force to be spread over a longer period of time.


Expanded Polystyrene (EPS) Foam
Energy-absorbing padding used to line the polypropylene shell of a child seat to protect a child’s head, torso and seat area, in case of a motor vehicle crash.

Expanded Polystyrene Foam EPS

Flexible LATCH
The lower anchor connectors of the Lower Anchors and Tethers for Children system that are permanently attached to the child seat shell using movable, flexible webbing.

flexible LATCH

Federal Motor Vehicle Safety Standard that pertains to all restraint systems intended for use as crash protection in vehicles for children up to 50 pounds.


Five-Point Harness
A child seat harness with five attachment points: two at the shoulder, two at the hips, and one between the legs.

five point harness

Forward-Facing Car Seat
A child seat meant to be used in a forward-facing position only.


Harness adjuster
Used to tighten and loosen the harness.

harness adjuster

Harness adjustment
The process by which the child seat harness is adjusted up or down to the appropriate height for the child occupant.


Harness Slots
The part of the child seat where the harnesses pass through from the front to the back of the restraint.

harness slots

Harness Strap
This refers to the child seat straps used to secure the child into the safety seat.

harness straps

BRITAX HUGS, Harness Ultra Guard System, are soft pads that work to reduce forward head movement in the event of impact.


Lap Belt
A safety belt anchored at two points, for use across the occupant's thighs/hips.


Lap/Shoulder Belt
A safety belt that is anchored at three points and restrains the occupant at the hips and across the shoulder; also called a “combination belt”.


The part of the buckle mechanism that slides into the buckle; usually the part that affects the length of the belt. Switchable latchplates have a lock button to allow the seatbelt to be locked around the child safety seat.


A steel bar extending along both sides of select BRITAX seats where the LATCH connectors are attached.  The LATCH bar adds additional reinforcement to the seat while also assisting in seat stability during side impact crashes when installed using LATCH.

latch bar

Locking Clip
A flat H-shaped metal clip intended to fasten together belt webbing (lap and shoulder portion) at a sliding latch plate, to prevent the webbing from sliding through.

locking clip

A built-in belt-locking feature on the child seat that works with certain types of safety belts in a similar fashion as locking clips.


Lower Anchors and Tethers for Children (LATCH)
A federally mandated attachment system for child seats. All passenger vehicles and child seats manufactured after September 1, 2002, are required to have special anchors for attaching the child seat directly to the vehicle rather than securing the child seat with the vehicle’s seat belt.


Multi-position buckle
A buckle which can be moved into different positions to ensure that the buckle strap is as close to the child as possible, while allowing for maximum comfort as the child grows.


National Highway Traffic Safety Administration (NHTSA)
The federal agency that oversees child passenger safety. NHTSA is dedicated to saving lives, preventing injuries and reducing economic costs due to road traffic crashes, through education, research, safety standards and enforcement activity.


No Re-thread harness
A harness which has an adjustment mechanism to easily adjust the height of the five-point harness as your child grows without requiring that the child seat be uninstalled from the vehicle in order to move the harness from one harness slot to the next.


Rear-Facing Infant Seat
A type of car seat specifically for use in the rear-facing position only.

infant car seat

A mechanism that rolls up the unused webbing of the safety belt when it is not in use and takes up slack around the user.


Seat Belt
The webbing, anchor and buckle system that restrains the occupant and/or child safety seat in the vehicle.

seat belt

Seat Bight/Seat Crack
The intersection between the bottom vehicle seat cushion and the back cushion.


The molded plastic structure of the child restraint.

car seat shell

Shoulder Harness Slots
Slots in the back of the child restraint through which the shoulder straps are routed.


Tether Anchor
Attachment point in vehicle for child safety seat tether strap. Refer to vehicle owner's manual regarding anchor location.

tether anchor

Tether Strap
An additional belt that anchors the top of the child safety seat to the vehicle frame; keeps the restraint from tipping forward on impact; can provide an extra margin of protection. 

tether strap


Sources: National Highway Traffic Safety Administration; Britax Child Safety, Inc.


 <-- Back to Car Seats 101