| Mode | Weight | Height |
|---|---|---|
| Rear-facing harness | 4–50 lb | 18–44 in |
| Forward-facing harness | 22–65 lb | 30–57 in |
| Belt-positioning booster | 40–120 lb | 40–57 in |
- Seat weight
- Not published
- Width
- Not published
- Usable life
- 10 years
- Aircraft
- Certified
Diono does not sell this seat on Amazon. See its own site for photos.
Diono Radian 3QXT FirstClass SafePlus (Radian 3QXT+) All-in-One Convertible Car Seat
An all-in-one car seat with 3 modes: rear-facing harness 4 to 50 lb, 18 to 44 in; forward-facing harness 22 to 65 lb, 30 to 57 in; belt-positioning booster 40 to 120 lb, 40 to 57 in.
At a glance
- Fits children from 4 to 120 lb
- Up to 57 in tall
- 3 modes: rear-facing harness, forward-facing harness, belt-positioning booster
- 10-year usable life
- Certified for aircraft use
Not sold on Amazon
Diono lists this seat on its US site. Buy from Diono or an authorized retailer, and confirm the exact model number before you buy.
Who is the Radian 3QXT FirstClass SafePlus (Radian 3QXT+) All-in-One Convertible Car Seat for?
The Radian 3QXT FirstClass SafePlus is an all-in-one car seat: rear-facing from 4 to 50 lb and 18 to 44 in, forward-facing with the harness from 22 to 65 lb and 30 to 57 in, then a booster from 40 to 120 lb. It adds an anti-rebound panel and toddler liner, and expires 10 years after purchase.
Reasons to consider it
- An anti-rebound panel: up for rear-facing, down as a comfort panel forward-facing
- A newborn protection insert for 4 to 10 lb and newborn harness pads
- A Side Impact Management pod for the door side
- A toddler liner for forward-facing and booster use
Things to weigh up
- Diono lists the seat at 32 lb
- The panel must never be in the up position when forward-facing
- The toddler liner is not for rear-facing, or with the infant support or newborn insert
- The 10-year life is split: 8 years in the 5-point harness and 2 years as a booster
My take on the Radian 3QXT FirstClass SafePlus (Radian 3QXT+) All-in-One Convertible Car Seat
The FirstClass suits a family that wants the 3QXT's newborn insert and Side Impact Management pod, plus an anti-rebound panel that folds down as a comfort panel when forward-facing, and a toddler liner. Diono lists it at 32 lb and 17 in wide, the same as the 3QXT. The 3QXT uses an anti-rebound bar instead of the panel and has no toddler liner.
A research summary of Diono’s published specifications and manual, read . Not a hands-on test or a crash-safety rating.
Who the Radian 3QXT FirstClass SafePlus (Radian 3QXT+) All-in-One Convertible Car Seat fits
This seat covers 3 stages, and a child has to meet every limit of the stage they are in. Diono gives it a 10-year life from the date of manufacture, so check the date label before using a hand-me-down.
- Rear-facing harness4 to 50 lb · 18 to 44 in
- The child faces the back of the car, which keeps the head, neck and spine supported in a frontal crash. Keep this mode as long as the child fits it.
- Forward-facing harness22 to 65 lb · 30 to 57 in
- The child faces forward in the seat’s own harness. Use the top tether every time, and stay in the harness until the child outgrows it.
- Belt-positioning booster40 to 120 lb · 40 to 57 in
- The seat raises the child so the vehicle’s own lap and shoulder belt sits on the hips and across the shoulder. The child has to sit properly for the whole ride.
What are the Radian 3QXT FirstClass SafePlus (Radian 3QXT+) All-in-One Convertible Car Seat weight, height and age limits?
| Mode | Child weight | Child height | Minimum age | Conditions |
|---|---|---|---|---|
| Rear-facing harness | 4 to 50 lb | 18 to 44 in | Not published | — |
| Forward-facing harness | 22 to 65 lb | 30 to 57 in | Not published | 22-30 lb must use the middle buckle slot |
| Belt-positioning booster | 40 to 120 lb | 40 to 57 in | Not published | — |
A child must meet every limit for the mode they use. The labels on your seat and its manual are the final word.
Radian 3QXT FirstClass SafePlus (Radian 3QXT+) All-in-One Convertible Car Seat specifications
- Seat weight
- Not published
- Width
- Not published
- Usable life
- 10 yearsTen years from date of purchase (8 years in 5-point harness, 2 years in booster)
- Aircraft use
- Certified for aircraft (see manual for which modes)
Will it fit your car?
Diono does not publish a width for this seat, so measure your back seat and compare it with the seat in a store before buying.
- Check your vehicle manual for lower anchor positions and any head-restraint rules.
- Rear-facing seats need front-seat room: try the install behind the driver before you commit.
- Certified for aircraft use, so it can travel as a seat rather than checked baggage.
What to know before you live with it
The anti-rebound panel
The anti-rebound panel is marked in the manual as FirstClass only. For rear-facing installs, Diono recommends it: the panel clicks into the slots on the front of the seat, then you press the hinge buttons and rotate the board up until it clicks. For forward-facing, it rotates down to the angle you want, and the manual says it is for comfort only there and not required. It must not be left up when the seat faces forward. To remove it, press the release buttons on the outside of the seat, one side at a time if needed.
Newborn parts and the toddler liner
Like the 3QXT, the FirstClass includes the newborn protection insert for 4 to 10 lb, which slides behind the infant support cushion and must not be used without it, plus newborn harness pads and a Side Impact Management pod for the door side. The toddler liner is FirstClass only. It is for comfort, does not affect safety, and is not for rear-facing installs or for use with the infant support or newborn insert. For forward-facing, the memory foam cushion goes inside it and the buckle threads through the slot for the child's weight; it always snaps to the cover.
Installation limits
Children under 22 lb or under one year old must ride rear-facing. Rear-facing, Diono recommends the detachable base with the anti-rebound panel; LATCH is allowed to 35 lb and the locked seat belt to 50 lb, with the head 1.5 in below the shell. Forward-facing covers 22 to 65 lb and 30 to 57 in, with LATCH to 40 lb, the middle buckle slot from 22 to 30 lb, and the adjustable bottom lowered over 25 lb. The top tether is recommended in the US and required in Canada. Booster mode, 40 to 120 lb, needs a lap/shoulder belt.
Cleaning and folding
Before washing, take the memory foam out of the seat pad and the wedges out of the infant support and newborn protection insert; the manual says the foam and wedges are not washed. Fabrics go in cold water on a gentle cycle with mild detergent, by machine or hand, and dry flat in the shade, with no bleach, ironing or dry cleaning. Straps are spot cleaned with warm water and mild soap and never soaked. To fold, move the side wings in, loosen the harness, pull the red release levers, and fasten the red carry strap to the first metal bar.
Is the Radian 3QXT FirstClass SafePlus (Radian 3QXT+) All-in-One Convertible Car Seat recalled?
- 17C003000: does not cover this model. The Part 573 report for campaign 17C003000 lists six models only: Radian R100 (model no. 16600 or 16000), Radian R120 (16800 or 16000), Radian RXT (16900 or 16000), Olympia (30100), Pacifica (30400 or 300000) and Rainier (30300 or 300000), built between November 25, 2013 and September 5, 2017. The Radian 3QXT FirstClass is a separately named Radian 3 series seat and is not among the listed models. Campaign source (read ).
Each campaign naming this family was read against this model’s numbers and build dates, and none covers it. Still check your seat’s model number and date of manufacture before use, especially on a used seat.
Radian 3QXT FirstClass SafePlus (Radian 3QXT+) All-in-One Convertible Car Seat: common questions
What are the Radian 3QXT FirstClass weight and height limits?
Diono lists 4 to 120 lb overall: rear-facing 4 to 50 lb, forward-facing 22 to 65 lb and booster 40 to 120 lb, with a maximum user height of 57.1 in. LATCH is limited to 35 lb rear-facing and 40 lb forward-facing.
Diono: Radian 3QXT FirstClass maximum height and weight (opens in a new tab)
How wide and heavy is the 3QXT FirstClass?
Diono lists it at 28.5 in tall, 17 in wide and 16 in deep, with a seat weight of 32 lb. Folded, the depth is 11.5 in.
Diono: Radian 3QXT FirstClass dimensions (opens in a new tab)
Can the 3QXT FirstClass fit 3-across?
Diono gives 51 in of vehicle seat width between the door handles as the minimum to fit 3 Radian models across.
Diono: Radian 3QXT FirstClass 3-across space (opens in a new tab)
Can I use the 3QXT FirstClass on a plane?
Diono says it is approved for aircraft only with the 5-point harness, rear- or forward-facing. It is not approved in booster mode, because aircraft seats have no shoulder belts.
Diono: is the Radian 3QXT FirstClass FAA approved (opens in a new tab)
When does the 3QXT FirstClass expire?
The manual says ten years from the date of purchase, with 8 years in the 5-point harness and 2 years in booster mode.
Diono Radian 3Q SafePlus Series manual (PDF) (opens in a new tab)
How is the Radian 3QXT different from the FirstClass?
Diono lists the 3QXT at 32 lb and 17 in wide with the same limits, a newborn insert and a Side Impact Management pod. It uses an anti-rebound bar rather than a panel.
Diono Radian 3QXT SafePlus support page (opens in a new tab)
Answers refer to the model and manual version on this page. Check the instructions supplied with your seat.
Before you buy
- Weigh and measure your child. The limits above are the manufacturer’s, and a child has to meet all of them for the mode they will use.
- Confirm the exact version. Colors, retail exclusives and model numbers change limits more often than you would expect.
- Read the manual before you buy, not after. It is linked above and holds the fit rules, the install methods and the expiry.
- Check recalls by model number and date of manufacture, and register the seat with Diono so you hear about the next one.
Sources
- Diono US product page
- Radian3Q_SafePlus_Series_English_Manual.pdf
- diono.zendesk.com/hc/en-us/articles/17137894364819-Radian-3QX-SafePlus-Radian-3QX-Manual
- Diono Radian 3Q SafePlus Series manual (PDF)
- Diono Radian 3QXT FirstClass SafePlus support page
- Diono: Radian 3QXT FirstClass maximum height and weight
- Diono: Radian 3QXT FirstClass dimensions
- Diono: Radian 3QXT FirstClass 3-across space
- Diono: is the Radian 3QXT FirstClass FAA approved
- Diono Radian 3QXT SafePlus support page
- NHTSA car seat guidance
Other Diono convertible car seats
| Model | Top child weight | Seat weight | Width | Usable life |
|---|---|---|---|---|
| Radian 3QXT FirstClass SafePlus (Radian 3QXT+) All-in-One Convertible Car Seat (this seat) | 120 lb | — | — | 10 years |
| Radian 3QX SafePlus All-in-One Convertible Car Seat | 120 lb | — | — | 10 years |
| Radian 3QXT SafePlus All-in-One Convertible Car Seat | 120 lb | — | — | 10 years |
| Radian 3R SafePlus All-in-One Convertible Car Seat | 120 lb | — | — | 10 years |
| Radian 3RXT SafePlus All-in-One Convertible Car Seat | 120 lb | — | — | 10 years |
| Radian 3RXT SafePlus Max All-in-One Convertible Car Seat | 120 lb | — | — | 10 years |
| Radian 3R All-in-One Convertible Car Seat | 120 lb | — | — | 10 years |
| Radian 3RX All-in-One Convertible Car Seat | 120 lb | — | — | 10 years |
| Radian 3RXT All-in-One Convertible Car Seat | 120 lb | — | — | 10 years |