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  • For Your Little One Stepup I-Size Belted 2/3 Car Seat Booster Seat - Slate Mist (4-12 Years)-Grade A Return
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For Your Little One

For Your Little One Stepup I-Size Belted 2/3 Car Seat Booster Seat - Slate Mist (4-12 Years)-Grade A Return

Good to know i-Size Belted Group 2/3 | No ISOFIX Needed | 4–12 Years
£30.00 £69.99 Save 57% Out of stock

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Suitable for children 100–150cm in height (approx. 4–12 years)

Group 2: 15–25kg (approx. 4–6 years) — Forward-facing
Group 3: 22–36kg (approx. 6–12 years) — High-back booster mode

Installation: 3-point seatbelt — compatible with virtually all vehicles, no ISOFIX required
Always check your child's height against the seat's headrest guide before use
1x Stepup i-Size Belted Car Seat (Slate Mist)
1x User Manual
✔ i-Size (R129) Certified — Exceeds current EU safety regulations
✔ Universal belted installation — no ISOFIX required, fits virtually any car
✔ Fits children 100–150cm (approx. 4–12 years) — Group 2 & 3
✔ Deep padded side-impact protection wings
✔ One-hand adjustable headrest — multiple height positions, no tools needed
✔ Premium breathable padding for all-day comfort
✔ Removable, machine-washable seat cover

**Please note, this item is a customer return. The item has been checked and all parts are in 'New' condition.

The item may not be shipped in its original packaging.

Customer warranty and rights remain.

For Your Little One Stepup i-Size Belted Group 2/3 Car Seat — Slate Mist. Designed to keep your child safe and comfortable from 100 cm to 150 cm (approximately 4 to 12 years), the Stepup i-Size Belted car seat is the last car seat you'll ever need to buy for this stage. Built to the latest UN R129 i-Size safety standard, it delivers superior side-impact protection and installs simply and securely using your car's existing seatbelt — no ISOFIX required.

Why Parents Love It

  • i-Size Certified (UN R129) — Exceeds current EU safety regulations for enhanced protection
  • Seatbelt Installation — Fits any car without ISOFIX, using your vehicle's existing 3-point belt
  • Fits 100–150 cm (approx. 4–12 years) — Grows with your child through Group 2 and Group 3 stages
  • Side-Impact Protection — Deep, padded side wings absorb and deflect impact energy away from your child
  • One-Hand Adjustable Headrest — Multiple height positions adapt quickly as your child grows, no tools required
  • Removable, Machine-Washable Cover — Easy to keep fresh and clean
  • Slate Mist Finish — Cool, understated tone that suits any car interior

Safety You Can Trust

The Stepup i-Size meets the stringent UN R129 regulation, which requires extended side-impact testing and a minimum height requirement — giving your child significantly more protection than older Group 2/3 seats. The belt-only installation means this seat is compatible with virtually any vehicle, making it a versatile choice for families with multiple cars.

Comfort for Every Journey

Thick, breathable padding and a one-hand adjustable headrest with multiple height positions mean your child can settle in comfortably whether it's the school run or a long motorway trip.

Specifications

  • Safety Standard: UN R129 (i-Size)
  • Child Height: 100–150 cm
  • Approx. Age: 4–12 years
  • Installation: Seatbelt (belted)
  • Facing Direction: Forward-facing
  • Cover: Removable & machine washable
  • Colour: Slate Mist
Black belted booster seat with padded headrest, armrests, and green side belt guides
For Your Little One Stepup I-Size Belted 2/3 Car Seat Booster Seat - Slate Mist (4-12 Years)-Grade A Return
£30.00
£30.00 -57%
£69.99
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Why you'll love it

Designed around family life

Discover the features, thoughtful details and benefits designed to make life with little ones easier.

i-Size Safety That Exceeds the Standard
01

i-Size Safety That Exceeds the Standard

The Stepup i-Size is certified to UN R129 — the latest and most rigorous car seat safety regulation in Europe. Unlike older Group 2/3 seats, i-Size requires mandatory side-impact testing, meaning your child is protected from impacts that traditional standards don't even test for. The belt-only installation means it fits virtually any car, making it an ideal choice for families without ISOFIX or those with multiple vehicles.
For Your Little One Stepup I-Size Belted 2/3 Car Seat Booster Seat - Slate Mist (4-12 Years)-Grade A Return
02

Grows With Your Child From 4 to 12 Years

Covering 100 cm to 150 cm in height, the Stepup takes your child through both Group 2 and Group 3 stages in a single seat — no mid-stage upgrades needed. The one-hand adjustable headrest moves in seconds to match your child's growing height, while the deep padded side wings reposition automatically to keep protection exactly where it's needed at every stage.
Comfort Built for Real Family Life
03

Comfort Built for Real Family Life

The breathable, premium-padded cover keeps them cool in summer and cosy in winter — and when it needs a refresh, simply remove it and pop it in the washing machine at 30°C. The cool Slate Grey finish brings a clean, contemporary look to any car interior and pairs effortlessly with modern family vehicles.
Designed for family life Comfort & practicality Made for everyday adventures

Customers praised this I-Size booster seat for its sturdy construction and ease of installation. The Slate Mist color received positive feedback for its smart appearance. Shoppers noted it's comfortable for children on both short school runs and longer journeys, with a compact design that doesn't take up excessive car space.

  • Really pleased with this booster seat. It feels sturdy and looks smart in the car.
  • Really impressed with the overall quality and how easy it was to set up.
  • The seat feels well made and my child seems comfortable in it, even on longer trips.
  • 5 stars: 49 (100%)
  • 4 stars: 0 (0%)
  • 3 stars: 0 (0%)
  • 2 stars: 0 (0%)
  • 1 star: 0 (0%)
E
Emma T.
Great booster seat

Really pleased with this booster seat. It feels sturdy and the Slate Mist colour looks smart in the car.

S
Sophie B.
Really pleased

Easy to fit using the car seat belt and straightforward to use on everyday journeys.

L
Laura W.
Easy to fit

The seat feels well made and my child seems comfortable in it, even on longer trips.

C
Charlotte D.
Good quality seat

Good quality booster seat and very simple to get fitted properly.

R
Rebecca E.
Very happy with it

Very happy with it. It feels secure once fitted and is easy for my child to use.

H
Hannah T.
Just what we needed

Just what we needed for our older child. Comfortable and not too bulky in the car.

S
Sarah R.
Comfortable and sturdy

Feels sturdy and well made and the Slate Mist finish looks really nice.

A
Amy J.
Simple to use

Simple to use day to day and getting the seat belt positioned is straightforward.

R
Rachel W.
Looks really smart

Looks really smart in the car and the colour is lovely in person.

J
Jessica H.
Great everyday seat

We use this every day and it has been practical and easy to live with.

C
Claire T.
Good value

Good value for the quality. It feels strong and nicely finished.

L
Lucy W.
Very impressed

Really impressed with the overall quality and how easy it was to set up.

K
Katie H.
Perfect for our car

Fits our car really well and gives our child plenty of room.

N
Nicola M.
Nice sturdy seat

Nice solid booster seat and easy to strap in for school runs and longer journeys.

E
Emily C.
Easy to install

Installation was straightforward and the instructions were easy enough to follow.

L
Lauren L.
Lovely seat

Very pleased with the seat. Comfortable, practical and looks good.

O
Olivia B.
Quick delivery

Delivery was really quick and the seat arrived well packed.

C
Chloe W.
Arrived quickly

Arrived sooner than expected which was great. Easy to get ready for use.

M
Megan K.
Helpful support

Had a question about the seat and support were really helpful and sorted it quickly.

A
Alice S.
Good overall

Overall a really good booster seat and exactly what we were looking for.

N
Natalie A.
Great booster seat

Really pleased with this booster seat. It feels sturdy and the Slate Mist colour looks smart in the car.

V
Victoria H.
Really pleased

Easy to fit using the car seat belt and straightforward to use on everyday journeys.

G
Grace M.
Easy to fit

The seat feels well made and my child seems comfortable in it, even on longer trips.

B
Bethany W.
Good quality seat

Good quality booster seat and very simple to get fitted properly.

L
Louise C.
Very happy with it

Very happy with it. It feels secure once fitted and is easy for my child to use.

S
Samantha H.
Just what we needed

Just what we needed for our older child. Comfortable and not too bulky in the car.

K
Kelly M.
Comfortable and sturdy

Feels sturdy and well made and the Slate Mist finish looks really nice.

J
Joanne E.
Simple to use

Simple to use day to day and getting the seat belt positioned is straightforward.

A
Abigail P.
Looks really smart

Looks really smart in the car and the colour is lovely in person.

J
Jennifer C.
Great everyday seat

We use this every day and it has been practical and easy to live with.

M
Melissa C.
Good value

Good value for the quality. It feels strong and nicely finished.

S
Stephanie B.
Very impressed

Really impressed with the overall quality and how easy it was to set up.

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