Britax Römer ADVANSAFIX i-SIZE car seat

UN R129 (i-Size) - 76 - 150 cm in height

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Based on the popular ADVANSAFIX IV R (the 3-in-1 chair with harness with the best score in the ADAC and RACE tests), the new ADVANSAFIX i-SIZE is an approved seat under the new ECE R129/03 standards suitable for children from 76 cm in height and 15 months old up to 150 cm. Thanks to the FLIP & GROW function, you can quickly change from the 5-point harness (76-102 cm or 21 kg) to the car's three-point seat belt with SecureGuard (100-150 cm). For extra protection, it features Isofix with Pivot Link, side impact absorption system SICT and XP-PAD pad (100-150 cm).


76-102 cm: 5 point harness

From 76 cm and 15 months of age to 102 cm in height or 21 kg in weight (whichever occurs first), the child is restrained with the 5-point harness, which distributes the impact forces across five points: two at the shoulders, two at the hips and one where the harness buckles between the legs.
The soft chest pads, made of neoprene, help reduce the child's forward movement in the event of an impact and provide greater comfort to the harness.


100-150 cm: 3-point seat belt with SecureGuard

From 100 cm to 150 cm in height, the occupant is secured directly with the vehicle's 3-point belt, in combination with the fourth contact point of the seat belt SecureGuard. This crotch harness ensures that the lap section of the seat belt remains in the optimal position on the hip, preventing it from rising dangerously towards the belly. The SecureGuard helps reduce abdominal forces by up to 35% in a frontal collision.

Easy transition with FLIP & GROW

When changing stages, the transition will be much easier thanks to the FLIP & GROW function. In this model, it is no longer necessary to remove any element from the seat, thus avoiding the possible loss of parts and allowing changing group at any time.

Just press a button to unlock the headrest and lift it to the required height, and stow the harness (without removing the chest pads) in the backrest, behind the seat fabric, so it won't get lost. The FLIP & GROW adjustment plate is then switched, turned to place the SecureGuard above the seat, and you’re ready to go!


When used as a non-integral restraint system (100-150 cm), the ADVANSAFIX i-SIZE adds the renewed XP-PAD pad, which covers the diagonal section of the seat belt and protects the child's neck and chest in the event of a collision or sudden braking.

According to tests carried out by the manufacturer in 2019, this shock absorption pad patented by Britax Römer diverts up to 30% of the energy from the child's delicate neck and prevents cervical hyperflexion by reducing head movement. In addition, it provides comfortable padding around the edges of the seat belt.

The XP-PAD has been optimized to allow an easier installation, a better retraction of the seat belt, greater comfort for the child and a more modern design, maintaining the same safety behavior in the event of a frontal impact.


V-shaped headrest

The V-shaped headrest has been designed to control head movement in the event of a side collision, while providing comfort. It can easily be adjusted with one hand, together with the five-point harness (76-102 cm), to adapt to the growth of the child.

ADVANSAFIX i-SIZE - Reposacabezas

EasyRecline for more convenience

EasyRecline is suitable for all ages and allows you to recline the seat into 3 comfortable positions. Even when the child is in the seat and without having to readjust the Top Tether.
ADVANSAFIX i-SIZE - Reclinación

Side protection with SICT system

Side impact protection from head to hip thanks to the backrest equipped with thick and soft padded sides, and the retractable Side Impact Absorption System (SICT) , which only needs to be adjusted on the side closest to the door.

Isofix con Pivot Link y Top Tether en forma de Y

ISOFIX connectors feature Britax Römer's patented Pivot Link, which directs the impact force first downward, pushing the seat against the vehicle seat, and then forward more gently. This reduces the risk of head and neck injury. The indicators let you that the ISOFIX connectors are anchored.
The Top Tether minimizes the rotation of the seat and therefore reduces potential damage to the head and neck area in the event of an accident. Due to its twin anchorage points, the Y-shaped Top Tether offers greater stability and security for the child compared to conventional Top Tethers.

ADVANSAFIX IV R - Pivot Link y Top Tether

Installation options

76 cm and 15 months - 102 cm or 21 kg of weight
- Isofix and Top Tether (universal approval).

100-133 cm. There are two options:
- With Isofix and three-point seat belt. If the car has i-Size seats, it is directly compatible (there is no need to consult the list of approved vehicles). If the car does not have i-Size seats, you need check the compatibility in the list of approved vehicles .
- With three-point seat belt (universal approval).

133-150 cm. There are two options:
- With Isofix and three-point seat belt.
- With three-point belt.
In both cases, it is necessary to check the list of approved vehicles to make sure that the car offers enough space to lift the headrest beyond 133 cm in height and, in the case of non-i-Size seats, that the seat belt buckle can be accessed easily and the retractor works properly when the headrest is adjusted.

Quick-remove cover

The padded seat cover is easily removable for machine washing without removing the harness. The chest pads can also be removed for washing.

Made in Germany

The ADVANSAFIX i-SIZE has been designed, developed and manufactured entirely in Germany, after undergoing numerous internal tests at the brand's own crash test facility, while the seat cover is produced in Europe.

Product specifications

With a width of 44 cm, it is possible to place three seats in the back seats of many cars, especially those equipped with i-Size seats or with ISOFIX in all three seats.
Forward facing seat from 76 cm to 150 cm in height.
Dimensions: 60-83 x 44 x 47 (height x width x depth)
Weight: 11 kg
Approval: ECE R129/03

ADVANSAFIX i-SIZE - Dimensiones


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