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Eternis S SensorSafe™ All-in-One Car Seat

CYBEX

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SOLD OUT

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Details & care

The only car seat your child will ever need, this convertible style offers state-of-the-art safety and comfort for your little one as a rear- and forward-facing car seat and as a high-back booster seat—on the job for up to 10 years.

Why parents will love it: With advanced safety features and easy installation and release, this convertible car seat monitors the well-being of your little one through the smart chest clip that syncs with the installed vehicle receiver and your smartphone.

Why kids will love it: The 12-position adjustable headrest and 3-position recline provides the ultimate in comfort and ergonomic positioning for rear-facing and forward-facing installations.

Child weight/height: Suitable from birth up to 120 lb.; rear facing from 4–50 lb.; forward facing from 22–65 lb.; belt-positioning booster from 40–120lb.

Safety features: The five-point harness takes safety to the next level with a chest clip featuring SensorSafe technology, which communicates with you via a receiver you insert into your vehicle's OBD-II port (it also connects to your smartphone), alerting you to unsafe conditions or if the baby has been seated too long or left in the car. A foam-lined energy-absorbing shell helps absorb the forces of impact to protect your child, while Linear Side-Impact Protection (L.S.P.) absorbs 25% more force in a side-impact collision.

Harness: 12-position height adjustable headrest with integrated no-thread, five-point harness for protection that grows with your child.

Car installation: Innovative one-pull LATCH system for easy installation and removal from the vehicle seat.

Stroller compatibility: N/A.

  • This car seat is eligible for return in its original, unopened box only
  • SensorSafe alerts you when child unbuckles the chest clip while still in motion; if child is seated for a prolonged period of time; if the temperature gets too hot or cold; or if child is still buckled in the car seat after you leave the vehicle, and notifies emergency contacts if no action is taken, sharing your location
  • Download the free SensorSafe app which also provides guidance on installation, how-to videos, FAQs and more, for Android or iOS
  • Magnetic buckle holders for easy in and out
  • Removable cupholder can be positioned on either side; dishwasher safe
  • Plastic/textile
  • Machine wash, line dry fabric
  • Imported
  • Item #5773076
  • Core Product ID 333335JHWN

Shipping & returns

Free shipping. Free returns. All the time. Purchases made online can also be returned or exchanged at any Nordstrom store, free of charge. Read more about our shipping & returns policies.

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Reviews

(40)403.8 out of 5
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Most helpful positive review

Oct 15, 2019Incentivized review

Best seat!

I’m a car seat safety nut! After doing a ton of research this was the seat! It’s amazing! It’ll definitely get us to 3/4 yrs for RF with its height/weight maximum. Super comfy for our son who is 13 months. I love that the head support adjusts with the straps to be just right for their little heads. You will not regret this purchase!
Twinsmumx4
5found this helpful

Most helpful critical review

Mar 26, 2025

Serious Safety Concern Chest Clip Easily Detaches

I purchased two of these car seats, and unfortunately, the chest clip is alarmingly easy to unfasten. My daughter is only 12 months old, and she can detach the chest clip using just her index finger. This poses a serious safety hazard—it’s terrifying to think what could happen in a car accident if the chest clip isn’t secured. Parents, please double-check your chest clips. Your baby’s safety could be at risk. When I called customer service to report the issue, I was told there was no warranty and that I had to contact the manufacturer directly. Nordstrom claimed they couldn’t do anything about it, which was incredibly disappointing.
NorahDeb
Verified purchase
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5 stars53%
4 stars10%
3 stars15%
2 stars10%
1 star13%
Oct 15, 2019Incentivized review

Best seat!

I’m a car seat safety nut! After doing a ton of research this was the seat! It’s amazing! It’ll definitely get us to 3/4 yrs for RF with its height/weight maximum. Super comfy for our son who is 13 months. I love that the head support adjusts with the straps to be just right for their little heads. You will not regret this purchase!
Twinsmumx4
5found this helpful
Aug 11, 2020

Didn't fit rear facing in my Mini

Bought this for my 2YO. He outgrew his infant carseat but I want to continue rear facing longer since it's safer & more comfortable. This didn't fit in my Mini rear facing. I moved up the passenger seat the furthest I can and it'll still push slightly against the car seat; I also had to put the seat more upright instead of reclined. This is pretty disappointing because he did look comfortable sitting in it when it was reclined. But it being upright rear facing makes his legs very cramped up looking. In our larger car, the Pilot, it fit but passenger can't lean too far back in order to get it to recline. I don't know what car would fit this full reclined and rear facing.
ThatKoolKat
4found this helpful
May 20, 2019Incentivized review

Thumbs Up!!

So far, so good. Material feels great. Like the fact that the cup holder is a clip up and optional to use.
Nash333
1found this helpful
Apr 19, 2019Incentivized review

Luxury Car Seat Worth Every Penny

This is a fantastic car seat. My toddler doesn't fight to get into the seat, and it is easy to buckle them in without the straps getting tangled (like with other models). The accompanying application and car adaptor are nice additional features. The tone that sounds when I turn off the vehicle when my child is in the seat is not bothersome. Overall, the CYBEX Eternis S is very well made, and if you can afford a luxury car seat, this one is worth every penny. #notsponsored
Waterlily2584
1found this helpful
May 20, 2025

My favorite

This is my second Eternis S and I love it. My son says it’s very comfortable and his head stays up when he falls asleep which is a huge bonus because he is always falling asleep in the car.
Verified purchase
Millsmachine
Mar 26, 2025

Serious Safety Concern Chest Clip Easily Detaches

I purchased two of these car seats, and unfortunately, the chest clip is alarmingly easy to unfasten. My daughter is only 12 months old, and she can detach the chest clip using just her index finger. This poses a serious safety hazard—it’s terrifying to think what could happen in a car accident if the chest clip isn’t secured. Parents, please double-check your chest clips. Your baby’s safety could be at risk. When I called customer service to report the issue, I was told there was no warranty and that I had to contact the manufacturer directly. Nordstrom claimed they couldn’t do anything about it, which was incredibly disappointing.
Verified purchase
NorahDeb
Size purchased:
One Size
Was this helpful?