This Glossary explains a few of the key terms and phrases that can be found throughout Car Seat Jungle. The Glossary is intended to clarify what we mean when we use certain terms in relation to car seats.

Car Seat Groups

A summary of the car seat groups available in the UK can be found in the table below. This is reflected in the free Car Seat Jungle Search Tool.

TypeGroup(for non i-size seats)Height Classification(for i-size seats)Weight Classification(for both i-size and non i-size seats)
Single group car seats
Infant0 and 0+40 - 87 cm0 - 13 kg
Toddler161 - 105 cm9 - 18 kg
Child2 and 3100 - 150 cm15 - 36 kg
Combination car seats
Infant / Toddler0+ and 140 - 105 cm0 - 18 kg
Toddler / Child1, 2 and 3N/A9 - 36 kg
Infant / Toddler / Child0+, 1 and 2N/A0 - 25 kg
All-in-One0+, 1, 2 and 3N/A0 - 36 kg
NOTE: above is a guide only! Check user manual for actual height and weight limits.


Car Seat Library: a directory of all car seats which are currently recorded in our master database and which are available in the UK. Each car seat has its own dedicated page containing key information and resources such as user manuals or installation videos.

Car Seat Search: Car Seat Jungle’s free tool to search for a car seat

Extended rear-facing: describes car seats which allow a child to travel rearward for longer. This means that Some extended rear-facing seats are designed for children up to 18kgs

i-size: is the latest european regulation (R129) with higher standards for safety testing and ease of use. The key changes include: advanced side impact testing, mandatory rear-facing until child is 15 months, height and weight based (previous regulation emphasised only weight) and ISOFIX only (prevents misuse).

ISOFIX: is an international standardised system for fitting child car seats or car seat bases. The way ISOFIX works is by using special attachment points built into the car seat or a car seat base which are then pushed into the right ISOFIX points in the car. Essentially, the car seat’s ISOFIX attachments simply ‘click’ into place and the car seat becomes part of the car’s metal structure. ISOFIX points in the car are metal mounts or hooks which are located in the seats at the back.

Although most new cars in Europe are fitted with ISOFIX, always double check in the car manual. Car seats with ISOFIX are safer than belted car seats because it’s easier to install a car seat with ISOFIX so the the risk of incorrect installation is minimised.

Side impact protection: the ability of a car seat to protect the child in the event of a crash to the side of the car. All car seats, with the exception of backless boosters, provide some side impact protection. Advanced side impact protection car seats provide additional protection in a side crash. New EU regulations (R129) require new i-size car seats to be tested in a simulated side impact crash, making these seats safer.