Eternis S SensorSafe Convertible Car Seat

by Cybex

Eternis S SensorSafe Convertible Car Seat

by Cybex



The CYBEX Eternis S is the only car seat that you'll need for your child. As a 3-stage all-in-one car seat, the Eternis S can be used as a rear-facing infant seat, then as a forward facing convertible seat and finally as a belt-positioning booster seat. The Eternis S offers an adjustable Linear Side-impact Protection (L.S.P. System), which absorbs up to 25% more impact forces in the event of a side impact collision and a patented 3-position reclining headrest, which helps prevent the child's head from falling forward while asleep, guiding the head and neck into a safe position. These features, combined with a steel reinforced frame for strength and durability provide advanced child safety protection and peace of mind.

Featuring the innovative SensorSafe technology to help prevent infant deaths in hot vehicles.  SensorSafe works by chiming the installed vehicle receiver to alert when a child is still secured in the back seat after the car has been switched off.  If no action is taken by the caregiver, then an alert is sent to the caregiver's cellphone through a downloaded app.  Finally, if required, a designated emergency contact will receive an alert with GPS coordinates of the vehicle's last known location. This state-of-the-art safety technology is designed so there is no need to reinstall each time you drive. For ease, just keep the receiver plugged into your car’s OBD port to drive with that extra peace of mind.

This is a Final Sale Product. No returns or exchanges. 


  • Protection that grows with your child – use Rear-facing from 4 lbs. to 50 lbs. Forward-facing from 22 lbs. to 65 lbs. and as a Belt-positioning Booster from 40 lbs. to 120 lbs.
  • Smart-tech harness chest clip with SensorSafe provides alerts when unsafe situations arise in the back seat (not used in Belt-positioning Booster mode) In-seat recline allows your child to safely ride rear-facing for longer
  • Linear Side Impact Protection System helps absorb up to 25% more impact forces* *when compared to the same car seat without L.S.P. extended
  • Patented headrest recline helps prevent sleepy heads from falling forward outside of the headrest safety zone
  • 12-position adjustable headrest with integrated no-rethread harness

What is SensorSafe Technology?

  • Chimes through the installed vehicle receiver if child is still secured in the seat when the car is switched off
  • Alerts through the caregiver’s cell phone if the child is left behind in the vehicle secured in the car seat and then alerts the designated emergency contact if the situation is still not remedied
  • Emergency contact receives GPS coordinates of the vehicle’s last known position
  • Alerts through the vehicle receiver and caregiver’s smart phone when the child has unbuckled their chest clip while the vehicle is in motion
  • Monitors the back seat temperature to alert through the vehicle receiver and the caregiver’s smart phone when the back seat appears to be too hot or too cold for the child’s comfort
  • Provides warnings to the caregiver when the child may have been seated for too long and needs a break
  • Receiver plugs directly into your car’s OBD port and syncs with the caregiver’s cell phone
  • Only one install needed if receiver is kept plugged into vehicle’s OBD port
  • Helps ensure proper use by providing guidance on installation, how-to videos, FAQ’s, direct link to customer service and more through the SensorSafe app
  • App can monitor up to 16 chest clips on a single platform
  • App download available for Android and IOS


  • Rear facing weight range: 5-50 pounds
  • Rear facing height range: 17-48 inches tall or until the child’s head is within 1 inch of the top of the headrest or backrest, whichever is higher. 
  • Forward facing height range: 28-49 inches tall 
  • Forward facing weight range: 22-65 pounds  
  • Booster mode weight range: 40-110 pounds 
  • Booster range height range: 44-57 inches tall 
  • Lower anchor weight limit: 40 pounds 
  • Seat weight: 25 pounds

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