- i-Size
- Lightweight
Klarna. Pay in 3 interest-free payments of £15.98. 18+, UK residents only. Learn more
At a glance
All features and specifications10% off eligible items when you spend £50+ with code TINY10
- Fast next-day UK deliveryOne-hour delivery window · reschedule by SMS
- Shipping to the US and the EUAdd 5–7 days to standard delivery
- Your order ships carbon neutralShipping and returns policy
- Secure, encrypted checkout
- Price match promise
- 60-day returns
About this product
Everything parents ask before they buy.
Description
The Junior Maxi i-Size R129 Highback Booster Seat offers lightweight, forward-facing safety for your growing child from 100–150cm (approx. 3.5 to 12 years). Rigorously tested and i-Size R129 certified, it provides enhanced side-impact protection and peace of mind for everyday journeys.
The 10-position height-adjustable headrest allows you to adapt the seat easily as your child grows, ensuring proper positioning and comfort throughout each stage. Designed for convenience, the seat features two hideaway cup holders, a removable, machine-washable cover, and a slim profile ideal for smaller cars or fitting multiple seats in the back row.
Installed using your vehicle’s 3-point seat belt, the Junior Maxi i-Size is a simple, no-fuss solution for families who need flexibility without sacrificing safety.
Features & benefits
- i-Size Safety Certification (R129)
Meets or exceeds the latest European regulations, offering maximum protection for children from 100 to 150cm in height. - One-Hand Adjustable Headrest
Easily adjust the headrest through 10 height positions to ensure the proper fit and head support as your child grows. - Side Impact Protection
Built-in features help absorb and reduce forces in the event of a side-on collision, enhancing all-around protection. - Belt-Fitted Installation
Installs securely using your car’s standard 3-point seat belt—no ISOFIX required, ideal for older vehicles or carpooling. - Comfort & Convenience
Includes two cup holders that tuck away when not needed, and a removable, washable seat cover for easy cleaning. - Slim, Lightweight Design
Weighing just 4.8kg, it's easy to move between vehicles and fits well in tighter car spaces.
Specifications
| Product Name | Junior Maxi i-Size R129 Highback Booster Seat |
|---|---|
| Child Height Range | 100–150cm |
| Age Suitability | Approx. 3.5 to 12 years |
| Installation Method | Forward-facing using the vehicle’s 3-point seat belt |
| ISOFIX Compatibility | Not ISOFIX compatible |
| Safety Standard | ECE R129 / i-Size certified |
| Side Impact Protection | Yes |
| Adjustable Headrest | 10 positions |
| Seat Cover | Removable and machine washable |
| Cup Holders | 2 hideaway holders |
| Dimensions | H81.5 x W45.6 x D39 cm |
| Weight | 4.8 kg |
| Brand | Graco |
| Product code | 8CT899HNTEU · 5060624774232 |
Delivery & returns
- Free mainland UK delivery over £35
- Shipping to the US and the EU: add 5–7 days to standard delivery
- 60-day returns on unused, unopened items
What else you need in the first years
Tick what you already have. We keep the rest in view, with the brands we know well.
See everything by stage- GracoCar seatYou're looking at it.
- JoviKids · KikkaBooPushchair0–6 mLie-flat for newborns, light enough for the bus.
- Little AcornsCot bed0–6 mFrom the first nights to the toddler bed.
- Tommee TippeeBottles and feeding0–6 mBottles, teats and everything to keep them clean.
- HauckHigh chair6–12 mFor weaning: an easy-wipe tray and adjustable height.
What parents say
No reviews yet. Bought one from us? Tell other parents how you got on, and add a photo.
Questions and answers
Will it fit my car?
Most cars with ISOFIX points fit. Send us your make, model and year and we will confirm before you order.
When will it arrive?
In-stock orders placed before 12pm on a working day are dispatched the same day. Mainland UK delivery is free on orders over £35.
Can I return it if it does not suit us?
Yes. You have 60 days to return unused, unopened items. See our returns policy.
Can I pay in instalments?
Yes. Choose PayPal at checkout to split the cost into 3 interest-free payments.
Not sure it fits?
Send us your car's make, model and year, or your child's height and weight. A member of our team will reply with what fits.