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Availability:
In Stock.
Arrives
Wednesday, Nov 4
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At a glance
- Condition
- New
- Color
- Raven Black 2.0
- Style
- One4Life Slim
- Model
- E1D407A
- Dimensions
- 18.5"D x 17.5"W x 24.5"H
- Weight
- 28 lb
- Material
- Polyester
Features 10
- ONE CAR SEAT FOR LIFE: Designed to grow with your child for 10 years, this all in one car seat easily converts from a rear facing infant and toddler car seat (5-50 lbs) to a forward facing car seat with a harness (30-65 lbs) and, finally, to a highback booster (40-120 lbs)
- FAST, SECURE, & PARET-FRIENDLY INSTALLATION: With ClickTight technology, you can install with confidence in 3 easy steps: pinch to open, thread and buckle, click it closed; the accessible color-coded belt paths make it easy to route the seat belt through the correct path for each mode
- SLIM 17.5 SPACESAVER DESIGN: Child car seat designed to fit 3 across* without compromising on trusted Britax safety or premium comfort, offering a slim outside and spacious inside. *Britax cannot guarantee 3-across installation fitment in all vehicles
- EXTENDED REAR FACING CAPACITY: Accommodates children up to 50 lbs and 49 rear facing, so your child can ride rear facing longer
- TRUSTED BRITAX SAFETY: This slim car seat features a patented V-shaped tether, SafeCell technology, a high-strength steel frame, and two layers of energy management. The seat is side-impact tested according to FMVSS 213a;* it is also tested to FMVSS 213 frontal-impact standards. The seat is verified by the Baby Safety Alliance. *FMVSS 213a sets side-impact standards for children up to 40 lbs and 43 with a 5-point harness. It does NOT include standards for testing harnessed children above 40 lbs and 43 or for booster mode
- NATURALLY FLAME-RETARDANT SAFEWASH FABRICS: The cover is safe to machine-wash and dry and naturally flame-retardant with no added FR chemicals
- EASY-ADJUST, 15-POSITION, NO-RETHREAD HARNESS: One-hand adjustments make it easy to find the right fit for your child as they grow; the 15-position harness and headrest move together easily no rethreading required
- QUICK-PUSH, 9-POSITION RECLINE: With easy-read indicator to help you find the correct angle for your vehicle
- 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; the slide-out cupholders are also dishwasher-safe for convenient cleaning
- TIMELESS AESTHETIC, PREMIUM COMFORT: This 3 in 1 car seat features soft knit fabrics in warm, neutral fashions with woven melange accents that are made from recycled polyester; One4Life Slim also includes plush padding, built-in cooling channels, three infant inserts, and a tag-free headrest
Description
The Britax® One4Life® Slim all in one car seat takes your child from birth to big kid with trusted Britax safety, ClickTight® installation, and a slim SpaceSaver™ design. As a 3 in 1 car seat, it’s designed to grow with your child for up to 10 years. One4Life Slim starts as a rear facing car seat with an extended capacity of up to 50 lbs, so your child can ride rear facing longer. It easily converts to a forward facing car seat (up to 65 lbs) and a highback booster car seat (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. This slim car seat features a high-strength steel frame, a SafeCell® 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.
Specs 24
| Maximum Weight Recommendation | 120 pounds |
|---|---|
| Minimum Height Recommendation | 18 inches |
| Minimum Weight Recommendation | 5 pounds |
| Maximum Height Recommended | 63 inches |
| Rear Facing Maximum Weight | 50 pounds |
| Forward Facing Maximum Weight | 120 pounds |
| Rear Facing Minimum Weight | 5 pounds |
| Forward Facing Minimum Weight | 30 pounds |
| Forward Facing Car Seat Minimum Height | 35 inches |
| Rear Facing Car Seat Maximum Height | 49 inches |
| Installation Type | Seat Belt |
| Orientation | Rear and Forward Facing |
| Harness Type | 5-Point |
| Number of Height Positions | 15 |
| Age Range Description | Kid |
| Infant Toddler Car Seat Type | Convertible Car Seat |
| UPC | 652182750756 |
| Manufacturer | Britax USA |
| Unit Count | 1 Count |
| Model Number | E1D407A |
| Part Number | E1D407A |
| Item Dimensions D x W x H | 18.5"D x 17.5"W x 24.5"H |
| Item Weight | 28 pounds |
| Material Type | Polyester |
No specs match.
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Wednesday, Nov 4
Yes, absolutely! You may return this product for a full refund within 90 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Fits 3 in Subaru Outback!
Color: Mineral Gray
Style: One4Life Slim
The look of this car seat is great. It’s got loads of padding, very sleek. Looks comfortable for my big toddler as well as my petite toddler. Needed to buy these to fit 3 across in my Subaru Outback. Easy to install, look durable. We’ve had them for more than 6 months and they hold up well. I feel that my kids are safe and well supported all while fulfilling the need to be slim in order to have 3 across by backseat. Right now we have 2 installed but already purchased the 3rd one for our newest baby. Would highly recommend.
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Reviewed in the United States on May 3, 2026 by Alyssa Quintana
Perfect Fit for My Audi e-tron and Incredible Quality! ⭐⭐⭐⭐⭐
Color: Parchment
Style: One4Life Slim
Perfect Fit for My Audi e-tron and Incredible Quality! ⭐⭐⭐⭐⭐ The Britax One4Life Slim has been an amazing upgrade for our car. It fits perfectly in my Audi e-tron, leaving plenty of space without feeling bulky, which is exactly what I needed. Installation was straightforward, the seat feels solid and secure, and the slimmer profile makes a huge difference in a more compact backseat layout. My child is comfortable, the padding feels premium, and the adjustability is excellent as they grow. I also love knowing this seat will last for years thanks to the all-in-one design. The fabric is easy to clean, the harness adjusts smoothly, and everything about it feels thoughtfully engineered. If you want a high-quality car seat that offers top-tier safety, comfort, and a great fit in smaller or electric vehicles like the e-tron, this is a fantastic choice. Highly recommend!
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Reviewed in the United States on November 7, 2025 by Jules
Love anything in AQUA family
Color: Sea Foam 2.0
Style: One4Life Slim
This color is one of my favorite and buy everything usually offered in it. However, as the grandmother now, I forget it’s best to get a darker shade to cover up dirt, stains etc. Lovely as it was, exchanged for the gray which turned out to be very close to the aqua. Regardless, extrely please with the ese of installation and my grandaughter LOVES the extra plushness, support and headrest.
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Reviewed in the United States on June 20, 2026 by CyndiontheGO
Will last until she doesn't need one
Color: Sea Foam 2.0
Style: One4Life Slim
Fits my granddaughter perfectly. I can easily work the straps and clips. It's made very well and will definitely last until she doesn't need one anymore.
Reviewed in the United States on July 20, 2026 by Heidi B.
Must Buy!
Color: Sea Foam 2.0
Style: One4Life Slim
Easy install! Love the color! Baby must think it is very comfortable as she falls asleep during every ride! Main reason for purchasing this car seat was that it allows the child to be rear facing to 50lbs which is more than any other seat I looked at, A+ for safety in my book! The seat fits well in my ford edge, with no issues of it getting in the way of the passenger seat!
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Reviewed in the United States on May 14, 2026 by BA Zaman
I am Britax mom for life now (prefer the regular size though)
Color: Parchment
Style: One4Life Slim
I am giving it a 4 star only because I LOVE the One4Life regular sized version better. Other than that... the clicktight install could make me give a 5 star anytime. I swear I don't understand how people have anything other than clicktight. I HATE borrowing people's car seats on vacation because if they don't have clicktight i cannot get them secured enough. But these are just so fast and effortless to install you won't be sweating and screaming at your kids. The colors offered for the Slim are why I tried this one instead of the regular size. I looove the colors! But I felt like my baby would flop his legs out of the frame of this car seat since it is slimmer, and with the regular he doesn't do that. It also feels more durable to me that the cupholders are built into the regular version, whereas the slim you have to install it. (PS there was no instruction on how to install the cupholders so I almost ended up breaking the darn thing until I found a way to do it on tiktok). Some people say they prefer the option to remove the cupholders since some kids try to put their feet in cupholders.... but i havent had that problem, and like i said my baby kept straddling the frame in a weird way that seemed unsafe to me compared to the regular size. But in general, the security of these britax one4life carseats is so obvious. They are so well built... I went and saw a Nuna Exec in person, which is meant to be the rolls royce of car seats at $800+ and i swear this Britax blew the Nuna out of the park in terms of looks and how durable it felt. I also heard the Nuna's are very hard to clean, and britax are so much more user friendly, and less expensive. I will never switch brands. I am a Britax fan for life now. I just hope they make the regular sized ones in cooler colors soon! The amount of time i put into researching this carseat was insane, because Im a crunchy mom haha no flame retardants was a big concern for me, and this one passes that test! It's also the best choice for moms with giant babies! My baby has always been 100th percentile, and the britax one4life (and the poplar i think too) are the best for height but also strap height. Bc sometimes babies can grow out the strap before the actual height if that makes sense. I want my baby to be safe rear facing for as long as possible, in a flame retardant free seat that is cozy, and this takes the cake! Oh also, my baby is happier in this carseat too. I've had him in graco's in the past when an airline lost ours and he would legit scream and cry. He seems so cozy in these. ANNDDD lastly, the way its sloped allows the driver to reach their arm back and assist (while looking in the camera i have by the radio in the car) to do stuff like pass a water bottle that has dropped or replace a binky. Ive tried in other car seats to do this and the heads are too oddly shaped to allow for it. Just buy this or the regular size and you will not be disappointed.
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Reviewed in the United States on November 3, 2025 by Emily Quigley
too heavy too hard to handle
Color: Sea Foam 2.0
Style: One4Life Slim
very hard for grandparents to carry it's extremely heavy. . We cannot get it installed in our car. The click tight part doesn't snap over our seatbelts so we're very frustrated. It's cumbersome not clear instructions about what part is supposed to fold down and it's not detailed enough or should have a video or somethingtoo much for us. I'm sorry I brought it. And it comes with over 40 pages of useless instructions. I wish I could give it a lower rating.
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Reviewed in the United States on May 6, 2026 by Mark R. Doran
Nice quality, but buckle is short and pinches legs
Color: Mineral Gray 2.0
Style: One4Life Slim
Wanted to love this car seat, but the crotch buckle is short. When my daughter sat in it, it pinched her thighs. I adjusted it and even spoke to a representative and still pinched her legs. The quality of the seat was nice, but had to return because of the strap issue. Other reviews mention this and there is info on Reddit talking about the same issue. I should have done more research before buying.
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Reviewed in the United States on July 28, 2026 by Jessica