| 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 3RXT SafePlus Max 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 26.5 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 3RXT SafePlus Max All-in-One Convertible Car Seat for?
The Radian 3RXT SafePlus Max is one of three all-in-one seats in Diono's Radian SafePlus Series. Its shared manual lists rear-facing from 4 to 50 lb and 18 to 44 in, forward-facing harness from 26.5 to 65 lb and 30 to 57 in, and booster mode from 40 to 120 lb. It expires ten years after purchase.
Reasons to consider it
- One seat from 4 lb rear-facing to 120 lb in booster mode
- Rear-facing up to 50 lb or 44 in
- Harness modes certified for aircraft
- A cover tool and removable cover for washing
Things to weigh up
- The manual does not publish what separates it from the 3RXT SafePlus
- LATCH ends at 35 lb rear-facing and 40 lb forward-facing
- Booster mode is not certified for aircraft
- Diono says three Radian models need at least 51 in between the door handles
My take on the Radian 3RXT SafePlus Max All-in-One Convertible Car Seat
It suits a parent who wants an all-in-one seat that comes with the optional SafePlus parts. The shared manual lists those parts only as included with select models, but Diono's box list for the Max names an anti-rebound panel, a Side Impact Management pod, an infant positioning liner and a newborn travel high wedge. Its weight, height and expiry limits match the 3RXT SafePlus in the same manual.
A research summary of Diono’s published specifications and manual, read . Not a hands-on test or a crash-safety rating.
Who the Radian 3RXT SafePlus Max 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 harness26.5 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 3RXT SafePlus Max 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 | LATCH installation limited to 35 lb |
| Forward-facing harness | 26.5 to 65 lb | 30 to 57 in | Not published | 26.5-30 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 3RXT SafePlus Max All-in-One Convertible Car Seat specifications
- Seat weight
- Not published
- Width
- Not published
- Usable life
- 10 years
- 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 and side impact pod
The manual describes these as parts included only with select models. The anti-rebound panel has two positions: up for rear-facing installs as an anti-rebound bar, and down for forward-facing as a comfort panel. The manual says never to use it up when forward-facing, and Diono recommends using it in both directions. It clicks into slots on the front of the seat. The Side Impact Management pod is described as an additional layer for side impact protection and goes only on the side next to the vehicle door. Both have release buttons or tabs for removal.
Rear-facing setup and the comfort insert
Rear-facing covers 4 to 50 lb and 18 to 44 in. LATCH is limited to 4 to 35 lb, and the seat belt covers 4 to 50 lb. Diono recommends the detachable rear-facing base. If you cannot get a good install with it on an elevated seat bight, the manual says to remove it and follow the blue level line instead. The comfort insert, a select-model part, is for smaller infants and includes a removable travel high wedge. The manual says their use is optional. Slide the buckle through the matching slot in the insert. The seat should move less than 1 in at the rear-facing belt path.
Forward-facing and booster rules
Forward-facing is 26.5 to 65 lb and 30 to 57 in, and Diono requires the top tether. Use LATCH only to 40 lb, then the lap/shoulder belt. The SafeStop is used from 26.5 to 40 lb and removed at 40 lb. The adjustable bottom is always lowered forward-facing and never used rear-facing or in booster mode. Booster mode runs from 40 to 120 lb and 40 to 57 in, with the harness removed and only the vehicle lap/shoulder belt. The child's shoulders must be at or above the 4th slot, and the headrest bottom should be even with the jaw.
Is the Radian 3RXT SafePlus Max 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 3RXT SafePlus Max 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 3RXT SafePlus Max All-in-One Convertible Car Seat: common questions
What are the Radian 3RXT SafePlus Max limits?
The shared manual gives rear-facing at 4 to 50 lb and 18 to 44 in, the forward-facing harness at 26.5 to 65 lb and 30 to 57 in, and booster mode at 40 to 120 lb and 40 to 57 in. The child is too tall above 57 in.
Diono Radian SafePlus Series manual (PDF) (opens in a new tab)
Does the 3RXT SafePlus Max come with an anti-rebound bar?
Diono's box list for the Max includes an anti-rebound panel (with an adjustable calf support cover), not a separate bar. It also lists the Side Impact Management pod, a 2-in-1 infant positioning liner, a newborn travel high wedge, a rear-facing base and 2 XL cup holders.
Diono support: Radian 3RXT SafePlus Max box contents (opens in a new tab)
Can a newborn use the Radian 3RXT SafePlus Max?
Diono says yes. It recommends rear-facing from 4 lb to 50 lb and says the Max comes with an infant positioning liner and a travel high wedge for a newborn.
Diono support: Radian 3RXT SafePlus Max for newborns (opens in a new tab)
Is the 3RXT SafePlus Max FAA approved?
The manual says it is certified for aircraft only in harness mode, installed with the lap belt instructions. It is not certified in booster mode because aircraft seats lack the shoulder belt it needs.
Diono Radian SafePlus Series manual (PDF) (opens in a new tab)
When does the 3RXT SafePlus Max expire?
Ten years from the date of purchase, according to the manual. Stop sooner if any part is damaged or missing.
Diono Radian SafePlus Series manual (PDF) (opens in a new tab)
How much front-to-back room does the Max need rear-facing?
Diono says it uses 30 to 36 in between the vehicle's back seat and the front seat back, depending on the shape and contour of the vehicle seats.
Diono support: Radian 3RXT SafePlus Max rear-facing space (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
- Radian_SafePlus_Universal_Manual_English.pdf
- diono.zendesk.com/hc/en-us/articles/32795154400147-Radian-3RXT-SafePlus-Max-Manual
- Diono Radian SafePlus Series manual (PDF)
- Diono support: Radian 3RXT SafePlus Max box contents
- Diono support: Radian 3RXT SafePlus Max for newborns
- Diono support: Radian 3RXT SafePlus Max rear-facing space
- Diono support: Radian 3RXT SafePlus Max 3-across space
- NHTSA car seat guidance
Other Diono convertible car seats
| Model | Top child weight | Seat weight | Width | Usable life |
|---|---|---|---|---|
| Radian 3RXT SafePlus Max 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 3QXT FirstClass SafePlus (Radian 3QXT+) 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 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 |