Diono Connect3 RXT 2-in-1 High-Back Booster

A 2-in-1 booster seat with 2 modes: high-back booster 40 to 120 lb, 38 to 63 in; backless booster 40 to 120 lb, 38 to 63 in.

At a glance

  • Fits children from 40 to 120 lb
  • Up to 63 in tall
  • 2 modes: high-back booster, backless booster
  • 8-year usable life
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.

Specifications checked against Diono’s US site and manual on . Not hands-on tested. How I research

Who is the Connect3 RXT 2-in-1 High-Back Booster for?

The Diono Connect3 RXT 2-in-1 is a belt-positioning booster that works as a high-back booster and, with the backrest removed, as a backless booster. The manual limits it to children 40 to 120 lb and 38 to 63 in, with LATCH/UAS connectors, and it expires eight years from the date of purchase.

Reasons to consider it

  • High-back and backless modes, both rated for 40 to 120 lb and 38 to 63 in
  • LATCH/UAS connectors, which can keep the booster secured when no child is in it
  • A two-stage recline to match the angle of the vehicle seat
  • A slide-in cup holder and snack tray that store under the seat

Things to weigh up

  • Diono's manual does not publish the seat's width, depth or weight
  • The armrests cannot be removed once they are attached
  • In backless mode the RED shoulder belt guide strap must always be used
  • Not certified for use in aircraft

My take on the Connect3 RXT 2-in-1 High-Back Booster

It suits a family that wants one booster to cover the high-back years and then convert to a backless seat, with lower anchor connectors to hold it in place. The trade-off is that Diono's manual does not publish a width or seat weight, even though Diono describes Connect3 as a booster that fits 3-across, so I would measure the back seat myself. Compared with the Connect3 RXT Backless, this version adds the backrest, the height-adjustable head support, a two-stage recline and the snack tray.

A research summary of Diono’s published specifications and manual, read . Not a hands-on test or a crash-safety rating.

Who the Connect3 RXT 2-in-1 High-Back Booster fits

This seat covers 2 stages, and a child has to meet every limit of the stage they are in. Diono gives it a 8-year life from the date of manufacture, so check the date label before using a hand-me-down.

High-back booster40 to 120 lb · 38 to 63 in
The seat’s own back and belt guide route the vehicle belt across the shoulder, and the sides give the child something to lean on when they sleep.
Backless booster40 to 120 lb · 38 to 63 in
Only the base is left, so the vehicle seat has to support the child’s back and head, and the belt guide sits at the hip.
A school-age child with a backpack beside an empty high-back booster

What are the Connect3 RXT 2-in-1 High-Back Booster weight, height and age limits?

Diono Connect3 RXT 2-in-1 High-Back Booster limits by mode
ModeChild weightChild heightMinimum ageConditions
High-back booster40 to 120 lb38 to 63 inNot published—
Backless booster40 to 120 lb38 to 63 inNot publishedChild's ears must be below the top of the fully raised vehicle seat or headrest

A child must meet every limit for the mode they use. The labels on your seat and its manual are the final word.

Connect3 RXT 2-in-1 High-Back Booster specifications

Seat weight
Not published
Width
Not published
Usable life
8 years
Aircraft use
Not certified for aircraft

How the Connect3 RXT 2-in-1 High-Back Booster installs

Lower anchors
LATCH/UAS connectors. Check your vehicle manual for which seating positions have anchors, and switch to the seat belt once the child passes the anchor weight limit in the manual.

Every install is a fit between one seat and one vehicle. Read both manuals, and use a free inspection station if anything is unclear.

An empty car seat installed on a back seat, seen through an open car door

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.
  • Not certified for aircraft use: plan on gate-checking it or using a different seat to fly.

What features does the Connect3 RXT 2-in-1 High-Back Booster have?

  • LATCH/UAS connectors

What to know before you live with it

How it installs

The child is always held by the vehicle's lap and shoulder belt. The manual forbids a lap belt only, and it lists motorized belts, dual retractor belts, inflatable belts and door-mounted belts as types that cannot be used. The LATCH/UAS connectors hold the booster to the vehicle's lower anchors: you press the cam lock lever, pull the connectors out, clip them on and tighten one strap and then the other. Diono notes the booster will still move against the vehicle seat with the connectors tight. Do not use LATCH/UAS if it interferes with the seat belt, and in a center seat make sure the booster does not rock side to side.

Source: Diono Connect3 RXT 2-in-1 and Backless Booster manual (PDF)

Head support, recline and belt fit

A single headrest and backrest height adjuster lever moves the head support. The manual sets the shoulder belt guide slightly above the child's shoulders, at least 1 cm. The lap belt sits in both lap belt guides, low on the hips, and the shoulder belt must not touch the neck. The two-stage recline lets the backrest match the vehicle seat; a gap is acceptable as long as the head support touches the vehicle seat back or headrest. Diono also says to pull webbing out of the retractor and let it feed back before each use, and never to lock the retractor. If the buckle is pulled across the lap belt guide into the seat, choose another seating position.

Source: Diono Connect3 RXT 2-in-1 and Backless Booster manual (PDF)

Converting to backless

To use it backless, you remove the backrest and fold the backrest insert under the cover of the seat bottom. The manual says that in backless mode the seat must be used with the shoulder belt guide strap, which is stored under the seat. You feed it between the backrest mounting bar and the seat base, then clip the RED guide onto the shoulder belt so it sits just above the shoulder. Backless use is only for children whose ears are below the top of the fully raised vehicle seat or headrest. The armrests, once fitted at first setup, stay on in both modes.

Source: Diono Connect3 RXT 2-in-1 and Backless Booster manual (PDF)

Covers and cleaning

The side-wing covers pull off over the side-wing pods; the manual says not to pull off the foam pads. The backrest and seat bottom covers come off by pulling the elastic loops over tabs around the shell and removing the plastic tab at the top of the headrest. Diono suggests taking phone photos during removal. Remove the seat cushion before washing and do not wash the seat foam. Machine wash the cover separately in cold water on a gentle cycle with mild detergent, or hand wash, then dry flat away from direct sunlight. No bleach, ironing or dry cleaning. The cup holder and snack tray are dishwasher friendly.

Source: Diono Connect3 RXT 2-in-1 and Backless Booster manual (PDF)

Is the Connect3 RXT 2-in-1 High-Back Booster recalled?

No campaign in the current NHTSA child-restraint data names this model family, and I have not run a separate review for it. Check your seat’s model number and date of manufacture before use.

NHTSA recall search · Recent car seat recalls

Connect3 RXT 2-in-1 High-Back Booster: common questions

What are the Connect3 RXT 2-in-1 weight and height limits?

The manual says to use it only with children who weigh 40 to 120 lb (18 to 54 kg) and are 38 to 63 in (97 to 160 cm) tall. The same limits apply in high-back and backless mode, and backless mode also needs the child's ears below the top of the vehicle seat or headrest.

Diono Connect3 RXT 2-in-1 and Backless Booster manual (PDF) (opens in a new tab)

When does the Connect3 RXT expire?

Diono's manual says not to use it once it is expired, which it defines as over eight years from the date of purchase. Keep your receipt or registration record so you know the date.

Diono Connect3 RXT 2-in-1 and Backless Booster manual (PDF) (opens in a new tab)

Can the Connect3 RXT be used on an airplane?

No. The manual states it is not certified for use in aircraft, because aircraft seats do not have the shoulder belts this booster requires.

Diono Connect3 RXT 2-in-1 and Backless Booster manual (PDF) (opens in a new tab)

Should I replace the Connect3 RXT after a crash?

In the U.S., the manual follows NHTSA: replace it after a moderate or severe collision, while a minor crash, as NHTSA defines it, does not automatically require replacement. In Canada, Diono says it must be replaced after any collision.

Diono Connect3 RXT 2-in-1 and Backless Booster manual (PDF) (opens in a new tab)

Does the Connect3 RXT need to be buckled in when no child is in it?

Yes. The manual says to secure it with the vehicle seat belt or the LATCH/UAS connectors even when it is unoccupied, because a loose booster could injure other occupants in a sudden stop or collision.

Diono Connect3 RXT 2-in-1 and Backless Booster manual (PDF) (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

  1. 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.
  2. Confirm the exact version. Colors, retail exclusives and model numbers change limits more often than you would expect.
  3. Read the manual before you buy, not after. It is linked above and holds the fit rules, the install methods and the expiry.
  4. Check recalls by model number and date of manufacture, and register the seat with Diono so you hear about the next one.

Sources

Other Diono booster seats

ModelTop child weightSeat weightWidthUsable life
Connect3 RXT 2-in-1 High-Back Booster (this seat)120 lb——8 years
Connect3 R 2-in-1 High-Back Booster120 lb——8 years
Connect3 R Backless Booster120 lb——8 years
Connect3 RXT Backless Booster120 lb——8 years
Cambria 2 2-in-1 High-Back Booster120 lb——8 years
Cambria 2XT 2-in-1 High-Back Booster120 lb——8 years
Everett NXT High-Back Booster120 lb——8 years
Monterey 2XT 2-in-1 High-Back Booster120 lb——8 years
Monterey 4DXT 2-in-1 High-Back Booster120 lb——8 years
Monterey 5iST FixSafe High-Back Booster120 lb——8 years
Monterey 6XT SafePlus High-Back Booster120 lb——8 years
Monterey 6DXT SafePlus High-Back Booster120 lb——8 years
Solana Backless Booster120 lb——8 years
Solana 2 Backless Booster120 lb——8 years