Sirona Q i-Size

Safely rear-facing from 45 cm up to 105 cm in height


UN R129/01



45 cm - 105 cm


max. 18 kg


From birth up to approx. 4 years

Sirona Q i-Size Stardust Black Sirona Q i-Size Midnight Blue Sirona Q i-Size Autumn Gold Sirona Q i-Size Stardust Black - Plus Sirona Q i-Size Midnight Blue - Plus Sirona Q i-Size Manhattan Grey - Plus

Sirona Q i-Size - Video

Sirona Q i-Size - More Info

Product information

  • Length:

    710 mm


    440 mm


    635 mm

  • Weight:

    15 kg

  • Maintenance:

    Fabric covers machine washable at 30°

  • What you get:

    Car Seat incl. Impact Shield, Rebound Bar, Storage Bag

  • Engineered and designed in Germany

    Engineered and designed in Germany

  • UN R129/01


The pictures of products and the measurements on this website are for indication purpose only. Products may vary and we reserve the right to make product changes.

Car compatibility

Is this the right seat for my car?

Before buying the child car seat, always check whether it can be properly installed in your vehicle. We recommend a test installation at a qualified retailer. Always follow the recommendations of the vehicle manufacturer regarding the installation of child car seats.

Installation with ISOFIX

Look for the i-Size logo in your vehicle.
If a vehicle seat is marked with this logo, it is suitable for use with all i-Size child car seats and therefore does not feature in our list of compatible vehicles.
If your vehicle does not have an i-Size seat, please check the list to find out whether your vehicle is compatible. If your vehicle is not listed, please contact our Customer Service team.

1. Select car manufacturer

2. Select model and year


Is it ok to keep using a seat after an accident?

We at CYBEX strongly recommend that you replace a seat after any kind of accident. This is because tiny hairline cracks, which may not be visible to the naked eye, can appear in the plastic parts of a seat after an accident. These cracks can pose an increased risk to safety.

My car seat is faulty, how can I get it repaired?

Please refer to the retailer where you bought your CYBEX seat. They will deal with the matter on your behalf.

Where can I get replacement parts for my product?

You can order replacement parts from a specialist retailer near you. To find a store near you, simply go to the store locator on our website:

What kind of clothing should my child wear when seated in the car seat?

Thick clothing prevents the harness from lying snugly against the body. This incorrect belt positioning could result in the harness slipping off the shoulder. For this reason, your child should wear everyday clothing. Thick clothing such as winter jackets should be avoided where possible. Once your child has been positioned in the seat, he/she can be covered with an extra blanket for warmth.

Can I use this seat on a flight?

No, this seat is not approved for use on an airplane.

Why only rearward-facing until 15 months and not for 4 years in total?

The head of a young child is large and heavy in proportion to the rest of their body and their neck is relatively weak. A rear-facing child restraint supports the head and neck and is thought, therefore, to reduce the risk of neck injury. Although this remains a topic for research, European regulators are satisfied that by 15 months, the neck has developed enough strength to withstand the forces in a typical crash. For this reason, 15 months was set as the minimum age for rear-facing. However, many R129 child restraints are approved for longer rear-facing use, for example, by children up to 105 cm (around 4 years).

Is my child allowed to rest his/her legs on the rebound bar?

Relatively tall infants may rest their legs on the rebound bar. Bending the legs at the knee does not affect safety in any way. As long as the child has sufficient legroom we recommend using the seat in a rear-facing position, which exposes the child to less force in the event of a collision.

Do both LSPs have to be extended for safety reasons?

To provide the best possible protection, the telescopic L.S.P. protector nearest the door should be extended as far as possible. It is designed with two settings. If in the longest setting, the L.S.P. touches the vehicle door, then the first setting must be used instead. When the seat is installed in the middle seat, the linear side-impact protection (L.S.P. System) should not be pulled out.

Can I use the seat and the base when the side airbag is activated?

Yes, side airbags may remain activated when using the baby seat.

How long should the newborn inlay be used?

The newborn inlay should be used up to a maximum height of 60cm (corresponding to approximately 3 months). As soon as the baby cannot be secured comfortably with the harness system anymore, the inlay should be removed.

When is a child too big for the CYBEX Sirona Q i-Size?

The CYBEX Sirona Q i-Size can be used by children up to a maximum height of 105 cm (maximum body weight: 18 kg). Depending on the child’s height, this corresponds to approximately four years of age.

When can I start using the Sirona Q i-Size in a forward-facing position?

Once your child has reached 16 months of age and height of 76 cm, the Sirona Q i-Size can also be used in a forward-facing position. This is not, however, mandatory. We recommend that children travel in a rear-facing position for as long as possible.

Can I use the Sirona Q i-Size without the newborn inlay even for a young baby?

No. The newborn inlay is specifically designed for premature babies and very small newborns and needs to be used from 45 to 60cm. Its purpose is to reduce the size of the seat to ensure these infants receive the best possible protection.

Why can’t I rotate the seat by a full 360°?

The sophisticated 360° rotating mechanism makes it easy to switch from a rear-facing to the forward-facing position - there is no need to remove and re-install the seat which can be an awkward task and cause back strain. Additionally, this mechanism allows the seat to be turned towards the door, making it easy to take the child in and out of the seat. In concrete terms, this means that the seat can be rotated to the left or right to face the door and can also be used either in a forward- or rear-facing position.

How can I convert the Sirona Q i-Size into a forward-facing seat?

We recommend using the Sirona Q i-Size in a rear-facing position for as long as possible to provide the highest level of safety. As soon as your child no longer has enough legroom in a rear-facing position, the seat can be used together with the impact shield in a forward-facing position. To do so, the harness first has to be tucked away in the seat so that the latter can be released. Subsequently, the seat can simply be rotated and your child can be secured with the impact shield. For further details on converting the seat, please refer to the instructions.

Can I also use the Sirona Q i-Size in a car without ISOFIX anchorage points?

The Sirona Q i-Size is an ISOFIX-only seat and can only be installed in vehicles with ISOFIX anchorage points.

What do I have to bear in mind when installing the Sirona Q i-Size in my vehicle?

The One-Click ISOFIX system makes it easy to install the seat in either a forward- or a rear-facing position and guarantees increased levels of safety. The integrated supporting leg provides additional stability and absorbs the forces released in a head-on collision. The Sirona Q i-Size can only be installed using the ISOFIX connectors.