Britax Roundabout G4 Convertible Car Seat - Onyx

This item is discontinued.
Britax Car Seat Travel Cart
FORM vwitem =1
Sales Rank =
Inventory isAvailable:1
Inventory qtyInStock:37
Britax Car Seat Travel Bag
FORM vwitem =2
Sales Rank =
Inventory isAvailable:1
Inventory qtyInStock:19
Britax Seat Saver Waterproof Liner
FORM vwitem =3
Sales Rank =
Inventory isAvailable:1
Inventory qtyInStock:12
Britax Kick Mat (2 Pack)
FORM vwitem =4
Sales Rank =
Inventory isAvailable:1
Inventory qtyInStock:13
Britax Car Seat Storage Pouch - D
20% OFF
FORM vwitem =5
Sales Rank =
Inventory isAvailable:1
Inventory qtyInStock:187
Britax Head & Body Support Pillow
FORM vwitem =6
Sales Rank =
Inventory isAvailable:1
Inventory qtyInStock:17
Britax EZ-Cling Sun Shade (2 Pack)
FORM vwitem =7
Sales Rank =
Inventory isAvailable:1
Inventory qtyInStock:7
Britax Back Seat Vehicle Mirror
FORM vwitem =8
Sales Rank =
Inventory isAvailable:1
Inventory qtyInStock:13

The Roundabout is purposefully designed and engineered to minimize the forward movement of the child’s head during a frontal impact to reduce the risk of head injury with the following revolutionary Britax head safety technologies:

Base with SafeCell Technology features SafeCells designed to compress in a crash, significantly lowering the center of gravity and counteracting the forward rotation of the child seat which normally propels the child toward the front seat

Integrated Steel Bars strengthen the connection to the vehicle and reduce forward flexing of the child seat during a crash

Energy-Absorbing Versa-Tether features a staged-release tether webbing to slow the forward movement, reducing the crash forces reaching the child, and a two-point attachment to minimize forward rotation while anchoring the top of the child seat

  • Side Impact Protection comprised of deep side walls lined with energy-absorbing EPP foam distributes crash forces, shields from vehicle intrusion, and contains the head, neck and body
  • Tangle-Free, Five-Point Harness distributes crash forces across the strongest parts of the body and provides a secure fit
  • 55-pound Weight Capacity for safety and comfort as your child grows
  • Rear and Forward Facing Recline for child comfort and positioning
  • High Density Comfort Foam provides an extra layer of padding to gently cushion your child
  • Two Buckle Positions for your growing child
  • Premium Lower LATCH Connectors for a quick and simple installation featuring a push button for easy release
  • Built-in Lock-Offs ensure a snug lap and shoulder belt installation with minimal effort
  • Anti-Slip, Contoured Base grips and protects the vehicle seat while offering optimum vehicle fit
  • Infant Positioning Pillow offers extra comfort while achieving proper harness fit for small infants
  • Certified for Aircraft Travel
  • Made in the USA with global components
Child Weight (lbs)Rear Facing: 5 - 40
Forward Facing: 1 year and 20, up to 55
Child Standing Height (in)46 or less
Child Seated Shoulder Height (in)Rear Facing: 9 - 15.75
Forward Facing: 12 - 15.75
Product Weight (lbs)17.6
Product Dimensions (in)18.5W x 26H x 21D
Seating Compartment Height (in)23.5
Seat Area Depth / Width (in)11 / 11
Shoulder Width (in)13
Harness Slot Heights (in)8.5 / 11.5 / 14 / 16.5
Buckle Strap Depths (in)5 / 7.5
Product Reviews
out of 5.0
6 Reviews
Ratings Snapshot
of Reviewers
Columbia, MD
Verified Buyer
Great Car Seat
June 29, 2015
It is great for overall and my baby feel comfortable setting on it.
Concord, NC
Verified Buyer
Great long-term use
August 24, 2014
We haven't used this seat much yet, but it's just as I expected it to be...great quality, good looking, and everything else you would expect from Britax. It's a great, long-term use seat and will definitely last for years to come.
Upstate NY
Verified Buyer
Better than expected
August 1, 2014
Like most parents, I want nothing but the best for my baby. This IMO is one of the best car seats at hands down the best price. I thought because it was one of the cheaper ones that Britax makes, that it would reflect in the quality of the product. Def is not the case here. It surpassed my expectations. I would hands down recommdend this to all parents on a budget and looking to protect their little one :)
  • Bigger than expected (good to me because I thought it was going to be small)
  • Well padded
  • Sturdy
  • Great material
  • Car seat is good for 6 years - unlike other makers that are only good for 5!
  • Still have to keep the passanger front seat up further than I'd like due to it being bigger. But all worth uit if baby is safe!
Winston Salem, NC
Verified Buyer
Great car seat.
May 31, 2014
We bought this car seat to use when we have our grandson with us. This type of car seat is much more bulky and heavier than the infant seats, so we decided it would be worth it to buy one for ourselves rather than constantly switch out the car seat from his parent's car. It has worked out great! It was delivered in just a few days, much quicker than we had anticipated.
  • Our one year old grandson is very comfortable in this car seat, and it appears to be highly rated for safety, which is the first priority. It is easy to get him buckled in quickly and easily.
  • There were so many options/directions given to install the car seat that it made the installation process much more involved than it needed to be. Our adult son did it for us in about one minute because he had done it before.
Tacoma, WA
Great Investment!
March 27, 2014
I love this carseat. My son is absolutely comfortable in it. We loved it so much that my Dad bought one for his car. The removable (and washable) padding, no-rethread straps, a very family friendly car seat. Highly recommend!
Houston, TX
Great design and safety
December 18, 2013
Its a simple car seat with very good safety ratings. My daughter loves it !
Customer Q&A