---
product_id: 682468124
title: "One4Life Slim All in One Car Seat, Up to 10 Years Use — Mineral Gray"
brand: "britax"
price: "¥266370"
currency: JPY
in_stock: true
category: "Britax"
url: https://www.desertcart.jp/products/682468124-one4life-slim-all-in-one-car-seat-up-to-10
store_origin: JP
region: Japan
---

# 15-position no-rethread harness Slim 17.5” SpaceSaver™ design ClickTight® 3-step installation One4Life Slim All in One Car Seat, Up to 10 Years Use — Mineral Gray

**Brand:** britax
**Price:** ¥266370
**Availability:** ✅ In Stock

## Summary

> 🚗 Elevate every ride with the Britax One4Life Slim—where safety meets sleek innovation!

## Quick Answers

- **What is this?** One4Life Slim All in One Car Seat, Up to 10 Years Use — Mineral Gray by britax
- **How much does it cost?** ¥266370 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/682468124-one4life-slim-all-in-one-car-seat-up-to-10)

## Best For

- britax enthusiasts

## Why This Product

- Trusted britax brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Space-Smart Design:** Slim 17.5” width fits 3 across in most vehicles without sacrificing comfort or safety.
- • **Effortless Installation:** ClickTight® system guarantees a secure fit in just 3 simple steps—no guesswork.
- • **Hassle-Free Maintenance:** Machine-washable recycled fabric cover and easy-clean shell keep your car seat fresh.
- • **Premium Comfort & Safety:** High-strength steel frame, SafeCell® tech, cooling mesh, and plush padding for every ride.
- • **Grow-With-You Versatility:** From newborn rear-facing to big kid booster—one seat, 10 years of use.

## Overview

The Britax One4Life Slim All-in-One Car Seat is a convertible, harness-to-booster seat designed to grow with your child from 5 to 120 lbs (up to 10 years). Featuring a slim 17.5” SpaceSaver™ design, patented ClickTight® installation, and advanced safety technologies like SafeCell® and a high-strength steel frame, it offers premium comfort with cooling mesh, multiple infant inserts, and easy one-hand adjustments. Its recycled, machine-washable cover and easy-clean shell make maintenance effortless, while the seat’s versatility and trusted Britax safety make it a top choice for modern families.

## Description

The One4Life(R) Slim all-in-one car seat takes your child from birth to big kid with trusted Britax safety, ClickTight(R) installation, and a slim SpaceSaver(TM) design. As a convertible and harness-2-booster seat in one, it grows with your child for 10 years. It starts rear-facing with an extended capacity of up to 50 lbs., so your child can ride rear-facing longer. It easily converts to forward-facing toddler mode (up to 65 lbs.) and high-back belt-positioning booster mode (up to 120 lbs.) when your child is ready. With a slim outside and spacious inside, the 17.5” seat is designed to fit 3 across* without compromising safety and comfort. ClickTight helps you install with confidence, every time. The base and shell are easy to wipe down for hassle-free cleanup. The car seat cover is safe to machine wash and dry, and it’s naturally flame-retardant with no added FR chemicals. One4Life Slim features a high-strength steel frame, a SafeCell(R) crumple zone, and a V-shaped tether. As your child grows, you can easily adjust the 15-position no-rethread harness and headrest with one hand. With cooling channels, premium padding, three infant inserts, and built-in armrests, your child will love every ride. *Britax cannot guarantee 3-across fitment in all vehicles.

## Features

- All-in-One Car Seat: One4Life(R) Slim is a convertible and harness-2-booster seat in one! It easily converts from a rear-facing infant and toddler seat (5-50 lbs.) to a forward-facing seat (30-65 lbs.) to a high-back booster seat (40-120 lbs.)
- ClickTight(R) Installation: Install with confidence in 3 easy steps: pinch to open, thread and buckle, click it closed!
- SpaceSaver(TM) Design: Slim outside, spacious inside! The 17.5” seat is designed to fit 3 across without compromising on trusted Britax safety and premium comfort *Britax cannot guarantee 3-across installation fitment in all vehicles
- Premium Car Seat Cover: Features a soft knit fabric with woven mélange accents that are made from recycled polyester; the cover is safe to machine-wash and dry and naturally flame retardant with no added FR chemicals
- Trusted Britax Safety: Features a patented V-shaped tether, SafeCell(R) technology, a high-strength steel frame, and two layers of energy management
- Comfortable Rides: This slim car seat includes soft comfort pads, built-in mesh cooling channels, three infant inserts, plush padding, and a tag-free headrest
- Easy to Adjust: The 15-position no-rethread harness and headrest adjust together easily with one hand, and the 9-position recline has an easy-read indicator to help you find the correct angle for your vehicle
- Slide-Out Cup Holders: The dishwasher-safe cup holders slide out with ease for convenient cleaning and click back into place for a secure attachment during rides
- Accessible Color-Coded Belt Paths: Make it easy to route the seat belt through the correct path for each car seat mode
- Hassle-Free Cleanup: Extra space between the shell and base means you can clean under the seat with ease – and with minimal grooves in the seating area and base, you can wipe it down with no fuss

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B0DPLJRD8Y |
| Age Range Description | Kid |
| Best Sellers Rank | #3,304 in Baby ( See Top 100 in Baby ) #14 in Convertible Child Safety Car Seats |
| Brand | Britax |
| Color | Mineral Gray |
| Customer Reviews | 4.4 4.4 out of 5 stars (230) |
| Forward Facing Car Seat Minimum Height | 35 inches |
| Forward Facing Maximum Weight | 120 pounds |
| Forward Facing Minimum Weight | 30 pounds |
| Harness Type | 5-Point |
| Infant Toddler Car Seat Type | Convertible Car Seat |
| Installation Type | Seat Belt |
| Item Dimensions D x W x H | 18.5"D x 17.5"W x 24.5"H |
| Item Highlight | Rear Facing, Forward Facing, & Booster Mode, 17. |
| Item Weight | 28 pounds |
| Manufacturer | Britax USA |
| Material Type | Alloy Steel, Plastic |
| Maximum Height Recommended | 49 inches |
| Maximum Weight Recommendation | 120 pounds |
| Minimum Height Recommendation | 18 inches |
| Minimum Weight Recommendation | 5 pounds |
| Model Number | E1D437B |
| Number of Height Positions | 15 |
| Orientation | Rear and Forward Facing |
| Part Number | E1D437B |
| Rear Facing Car Seat Maximum Height | 49 inches |
| Rear Facing Maximum Weight | 50 pounds |
| UPC | 652182750008 |
| Unit Count | 1 Count |

## Product Details

- **Brand:** Britax
- **Color:** Mineral Gray
- **Installation Type:** Seat Belt
- **Material:** Alloy Steel, Plastic
- **Orientation:** Rear and Forward Facing

## Images

![One4Life Slim All in One Car Seat, Up to 10 Years Use — Mineral Gray - Image 1](https://m.media-amazon.com/images/I/81BaqeJpe6L.jpg)

## Available Options

This product comes in different **Color, Style** options.

## Frequently Bought Together

- Britax One4Life Slim All-in-One Car Seat, 10 Years of Use, 17.5” SpaceSaver Design, Converts from Rear-Facing Infant Car Seat to Forward-Facing Booster Seat, ClickTight Installation, Mineral Gray
- Britax Anti-Rebound Bar Accessory - Compatible with Britax One4Life Car Seats , Black
- Britax Car Seat Waterproof Liner - Moisture Wicking Fabric + No Slip Grip + Machine Washable + Crash Tested

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*Product available on Desertcart Japan*
*Store origin: JP*
*Last updated: 2026-09-27*