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Radian® 3R®

(You save $30.00 )

The original 3 Across All-In-One™ convertible car seat

(You save $30.00 )
or 4 interest-free payments of $42.50. Learn More
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Radian® 3R®

The original 3 Across All-In-One™ convertible car seat - now available in new, two-toned colorways with additional features. Up to 10 years of safe use and great value.

Granted by the Insurance Institute for Highway Safety (IIHS), the BEST BET award is bestowed to car seats and boosters that provide good belt fit for typical ages approximately from 4 to 8 years old in almost any car, minivan, or SUV. The IIHS is an independent, scientific, and educational organization dedicated to reducing injuries and property damage from motor vehicle crashes through the education of consumers, policymakers, and safety professionals.


  • 10 Years 1 Car Seat® - from Birth to Booster (5 - 120 lb) it's all you will need. Grows with your child, ultimate protection on every road trip. 4 modes in 1 seat!
  • Rear Facing for Longer - lovingly engineered to keep your child rear-facing up to 50 lb.
  • Fits 3-Across - our famous slim-fit design with zero compromises to safety, space, or comfort.
  • Mechanically engineered from reinforced automotive grade high-strength steel, our unique core shell shields and protects your child.
  • High-quality ComfortPlus Memory Foam, always included.
  • The original and only all-in-one convertible car seat that folds for travel or compact storage. FAA approved for airline use.
  • Comfort Support - head support pillow, comfort cushion and 2 XL cup holders. Additional features are exclusive to the following colorways: Black Storm, Blue Surge, Blue Razz Ice, Purple Wildberry and Pink Cotton Candy.

Product Specs

  • Minimum User Weight: 5 lb
  • Maximum User Weight: 120 lb
  • Minimum User Weight - Rear Facing: 5 lb
  • Maximum User Weight - Rear Facing: 50 lb
  • Maximum User Weight - Rear Facing LATCH: 35 lb
  • Minimum User Weight - Forward Facing: 22 lb
  • Maximum User Weight - Forward Facing: 65 lb
  • Maximum User Weight - Forward Facing LATCH: 40 lb
  • Minimum User Weight - Booster: 40 lb
  • Maximum User Weight - Booster: 120 lb
  • Maximum User Height: 57.1 in
  • Product Height: 28.4 in
  • Product Width: 16.9 in
  • Product Depth: 16.1 in
  • Seat Weight: 23 lb (Black Jet, Gray Slate, Blue Sky, Pink Blossom, Red Cherry)
  • Seat Weight: 23.37 lb (Black Storm, Blue Surge, Blue Razz Ice, Purple Wildberry, Pink Cotton Candy)

Care & Maintenance

Covers: Machine wash cold, line dry. Shell and Components: Spot clean

Warranty Information

12 months standard warranty - join lifetime journey care for up to 10 years extended warranty

Car Seat, Product Manual, Safe Stop®, Lap Belt Cushion, Rear-Facing Base, Harness + Buckle Pads

We recommend the following Diono® Accessories: Angle Adjuster®, Car Seat Travel Backpack, Ultra Mat™, Easy View Mirror®

Yes, you should always read your Radian® 3R® product manual and the vehicle's manual that you plan to install it in before use and is sewn into the seat cover. Find more information in our safety hub here.

Your manual is located in a pouch sewn into the seat cover on the back of the seat on the left hand side about half way up the backrest underneath the seat cover. Here is a video that shows you here.

Yes, your Radian® 3R® is entirely suitable for a newborn. We recommend rear-facing from 4 lb to 50 lb as this is the safest way for a young child to travel. Learn more here.

Yes, your Radian® 3R® is suitable for your toddler. We recommend rear-facing up to 50 lb/forward-facing from 50 lb to 65 lb in the 5-point harness system.

Yes, your Radian® 3R® is suitable for your big kid. We recommend forward-facing in the 5-point harness system (up to 65 lb) then as a high back booster up to 120 lb.

When installing your Radian® 3R® rear-facing in some vehicles, the space-saving Angle Adjuster® can make more space available behind the front seat. Check out the video here.

Only use Diono® approved and crash-tested accessories with your Radian® 3R®. The accessories you can use are here.

Diono® is the only car seat manufacturer to offer a folding convertible car seat. This makes it the perfect travel seat as it is so compact and folds into a handy car seat travel backpack. Saving space for trunk or home storage.

51 in is the minimum vehicle seat width needed between the vehicle's interior structures to fit your Radian® 3R®. The Radian® fits 3-across in most mid-sized Sedans up. Learn more here.

Your Radian® 3R® can be used rear-facing up to 50 lb or 44 in height. We encourage rear-facing as long as possible since it is the safest way for children to travel!

You can use your Radian® 3R® until 65 lb forward-facing with the 5-point harness and then until 120 lb as a high back booster.

Your Radian® 3R® uses 30-36 in between the vehicle's backseat and front seat back, depending on the vehicle's seat shape and contour. Fitting in most vehicles' rear-facing, use our space-saving Angle Adjuster® if more space is needed.

No. Always follow our guidelines regarding use of items not included with the car seat. We only recommend the use of accessories and spare parts from Diono® as all of these have been tested for use with your Radian® 3R®.

No, the Radian® 3R® does not come with a cup holder, but you can purchase them separately here.

Our car seat fabrics are tested to ensure they do not contain any legally restricted harmful flame retardants. In order to meet Federal and Canadian Motor Vehicle Safety Standards for flammability, our car seat fabrics do contain flame retardants.

Safety is paramount. Diono® ensures compliance with US Federal Motor Vehicle Safety Standards (FMVSS), US National Highway Traffic Safety Administration (NHTSA), and Canadian Motor Vehicle Safety Standards (CMVSS), regularly testing all car seats.

All Diono® convertible car seats have a life span of 10 years, starting from when you purchase your seat. If the date of purchase cannot be determined then we use the date of manufacture.

Each Radian® is hand built by our manufacturing partners overseen by our highly trained quality control team.

Your Radian® is heavy as our engineers will never compromise on the intergity of the famous Diono Steel core. Since launch our reinforced automotive grade high strength steel core is the heart of our Radian, protecting generations of kids everyday.

Your Radian® 3R® has a low seat base because as your child grows, they will want to get in and out of your car themselves. This low height makes it very easy for them to get into their seat before you harness them up.

The seat sides on the base expand as your child grows. Parents and kids really love this feature on the Radian® 3R® as it makes travel so much easier