ITEM# 518000387

Cybex Sirona M Convertible Car Seat - Pepper Black

This item is discontinued.
The CYBEX Sirona M Convertible Car Seat has two modes - rear-facing from 5 lbs. to 40 lbs. and forward-facing from 22 lbs. to 65 lbs. This seat provides comfort and maximum safety with patented Side-impact Protection which can reduce side impact forces by up to 25%*, an energy absorbing shell and a 12-position height adjustable headrest with a no-rethread harness that offers protection that grows with your child.

Linear Side-Impact Protection (L.S.P.)

The L.S.P. System of the Sirona M and Sirona M with SensorSafe extends on the door facing side of the installed car seat and offers increased safety during a side-impact collision. The L.S.P. System reduces the forces of an impact in the event of a side-impact collision by approximately 25% when compared to the same car seat without L.S.P. extended..

12-Position Height Adjustable Headrest

The 12-position, height-adjustable headrest of the Sirona M and Sirona M with SensorSafe offers comfortable protection as your child grows. The integrated no-rethread harness adjusts with the headrest movement so there’s no need to reconfigure the harness as your child moves up in the seat.

Energy-Absorbing Shell

An energy absorbing shell helps reduce the forces felt by the baby in the event of a collision.

10-Position Reclining Backrest

One-hand recline for rear-facing and forward-facing installations.

Magnetic Buckle Holders

Magnetic buckle holders for easy entry and exit from the seat.

Removable Newborn Inlay

Removable newborn inlay provides additional support for smaller babies.

Innovative One-pull Latch Removal System

For easy installation and removal from the vehicle seat.

Removable Cup Holder

Removable cup holder can be positioned on either side and is dishwasher safe for easy clean up.


  • Adjustable Linear Side-impact Protection (L.S.P. System) absorbs up to 25% more impact forces in the event of a side impact*
  • Magnetic belt holders for easy entry and exit from the seat
  • Rear-facing installation from 5 lbs. to 40 lbs., or Forward Facing from 20 lbs. to 65 lbs.
  • 12-position, height-adjustable headrest with an integrated no-rethread harness for protection that grows with your child
  • 10 position one-hand adjustable recline for the best fit to your car
  • Cup holder can be positioned on either side and is dishwasher safe for easy clean up
  • Energy absorbing shell helps reduce the forces felt by the baby in a collision
  • Dual Belt adjusters to ensure a tight fit
  • Dual-level indicators to help ensure the proper angle
  • Innovative one-pull LATCH removal system
  • LATCH Connection storage provided in the seatback when not in use
  • Ergonomic design in CYBEX’s iconic Gold Design language
  • Designed and engineered in Germany
*when compared to the same car seat without L.S.P. extended
Product Reviews
out of 5.0
16 Reviews
Ratings Snapshot
of Reviewers
Verified Buyer
Comfortable, cozy
March 20, 2023
  • Very Comfortable
Best Uses
  • Road trips!
  • Heavy, wide.
Tampa, fl
Verified Buyer
Great carseat
January 26, 2022
Have this as my second car seat. Very comfortable and easy to use! Difficult install, but feels sturdy and overall very pleased. My daughter seems to enjoy it!
Rockwall, Texas
Verified Buyer
Best car seat
September 1, 2021
We love this car seat. We had many different car seats and this cybex car seat is our favorite
Ginny F.
Verified Buyer
Very nice car seat
July 9, 2021
I purchased this for my Grandbaby. It is the second baby convertible car seat I purchased for son and daughter-in-law. They love it. The gray color is lovely and the carseat isn't difficult to install. We chose this car seat because it seems safer for right or left backseat window seat than in the middle of backseat when driving 2 children in carseats. The engineering is excellent and the carseat seems very comfortable for baby. I would definitely purchase this car seat again. For the parents that complain that car seat seems heavy...well I want a solid and safety minded convertible car set for my grandchildren that will last for years! And this car seat is not overly heavy...It is designed with safety and durability in mind and I appreciate that immensely. The first car seat I purchased was the NUNA RAVA and this car seat is comparable for less money.
Pasco, Washington
Verified Buyer
Loved it
April 28, 2021
I got this on sale and it was a steal! I loved it
Miami, FL
Verified Buyer
We live this car seat!
April 5, 2021
We ordered this car seat when my baby turned 1 year! It’s perfect. Adjustable! And now she is almost 2 so we adjust the car seat for her weight and height! Very easy.
  • Material good quality. Easy to clean
  • No cons
Verified Buyer
Sturdy stationary car seat
January 21, 2021
Hi bought this after doing some research. I also wanted something for my son that would grown with him. The seat is heavy which makes it sit sturdy once you instal it in your car . The cushions are comfortable and good quality. It has magnetic sides to hold the buckles . The only thing is it is super hard to figure out how to instal at first . I struggles for a long time . Also if you have to reinstall it In the car it takes sometimes a few times to get everything lined up with the locking in the seatbelt . Also you need to take the whole seat out to adjust the recline part. It does say that you can put a newborn in there but it is pretty if and I feel like my son would have been swimming in it at first but he is long so had to switch to this car seat at 5 months . I do wish is was easier and there were better directions to instal.
  • Heavy and secure , comfortable cushions, easy to adjust straps , different recline options
Best Uses
  • To grow with your child so you don?t need another car seat at all !
  • Hard to instal , have to take out to adjust recline
Raleigh, NC
Verified Buyer
Like it so far
November 30, 2020
No complaints. We have the eternis for our other seat and this is pretty similar. Only thing I didn't notice before we ordered was the orange stripe across the seat under the newborn insert. Other than that love how cushioned it is and the reclining feature.
Verified Buyer
Compact Convertible Car Seat
October 11, 2020
We love this car seat! It fits in rather small spaces and gives the front seat passenger a good amount of room. Easy to install and adjust harness and headrest. The only concern is that the headrest feels like it could break with enough force, but it hasn't happened in the year that we've had it.
Verified Buyer
Love this car seat
September 25, 2020
I Love this toddler car seat. Very Safe and comfortable for my child. All Cybex products are reliable and safe.
Atlanta, ga
Verified Buyer
Not bad
September 17, 2020
The seat is comfortable for my 7 month old . It’s not as light or as heavy not so bad without the sensor.
My baby girl enjoys this seat with cute cup holder
Glasgow, West Virginia
Verified Buyer
September 2, 2020
Best car seat around! Fast shipping.
  • Fast shipping
  • Quality
Rio Linda, California
Verified Buyer
Love it!
August 5, 2020
I love this car seat! Its really just a great purchase over all . It also shipped really quick and it looks very nice ! My son love it :)
  • Looks nice, light weigh, cup holder, fast shipping, convenient to have seeing thaf kids grow fast!
  • Its a little bulky but not to bad! Not to much to complain about.
Essex, Maryland
Verified Buyer
Spacious and Comfortable Carseat
August 4, 2020
This car seat is very spacious so there is plenty of room for baby to grow. The design is really nice and looks very sleek. I couldn’t be happier with this car seat!
K G.
Chicago IL
Verified Buyer
Very safe and durable car seat
August 1, 2020
I was interested in convertible car seat only and this one seems work for us. My 7 lb baby loves it and she feels very comfortable in there ( infant padding insert works very well)
Customer Images
  • Good convertible car seat from 5lb to 65lb just what I was looking for.
  • It might not feet very well in small car. In baby position car seat takes a lot of space , we had to move front passenger seat little bit to make room for this seat.
Loren L.
Dardenne Prairie, Missouri
Verified Buyer
Best car seat buy!!
June 23, 2020
Not difficult to install, and the seat adjustment Is so simple. Extra roomy and appears comfortable for my 11 month old.
  • Magnetic strap clip holders
Customer Q&A
2 Questions & 2 Answers
Britney J
from Gilbert, Arizona asked:
November 17, 2020
What are the weight and dimensions of this seat?

Rear-facing dimensions (fully reclined): 18.5"H x 20"W x 29"D

Forward-facing dimensions (fully upright): 25"H x 20"W x 21.5"D

Product weight: 24.7 pounds

Rear-facing capacity: Birth to 40 pounds

Rear-facing capacity: 22 to 65 pounds or 49"

Submitted by: Albee Baby on November 17, 2020

from IL asked:
August 17, 2020
Hello, is cup holder included?
Submitted by: Albee Baby on August 18, 2020