select your color
$199.99 – $249.99
the original monterey® booster has evolved!
Back in 2008, the original American expandable booster seat was created right here at Diono. Fast forward to today as we welcome the next evolution in a long-standing legacy. We’ve taken the award-winning Monterey and painstakingly engineered 15 upgrades to create the Monterey® 4DXT. From the remodeled headrest, enhanced fabric covering, contoured seat base and breathable exo-shell panels, we’ve considered every last detail to create a contemporary new look.
Lowest Headrest Position
Sidewings minimum width
Highest Headrest Position
Sidewings maximum width
Backless Booster Mode
This booster seat is amazing. It literally grows with your child and that’s super helpful since car seats are really expensive and children grow so fast! You can raise both the headrest and expand the hip part of the seat. It then converts to a backless booster when your child is ready.
why parents love me
< swipe for more >
16.98lbs / 7.7kg
care & maintenance
cover machine washable at 86F/30C/Cold
why parents chose me
We’ve taken all the unique and well-loved features from our award-winning Monterey and introduced 15 upgrades in safety, comfort and style.
8 years of adventure
Like all Diono boosters, expect up to 8 years of service, so you can rest assured the Monterey 4DXT will be with you for the long haul.
The height and width can be adjusted independently for safety that envelopes their head and shoulders up to 12 years of age.
side impact protection
Features the Diono 3-layer Side Impact Protection System built in. From the EPP foam coating to the molded rigid shell casing, we’ve got your little one covered.
total child comfort
The ergonomically contoured seat base and remodeled headrest improves the child seating position with luxury AIRTEK foam cushioning for total child comfort.
always travel ready
The Monterey booster seat is super portable, lightweight and easy to store with a great flat pack feature that makes for a perfect travel companion for your little one.
award winning car seats
parents love the 4DXT!
can the Monterey® 4DXT fit 3-across?
No, it is too wide to fit 3-across.
how do you install the Monterey 4DXT?
There is no installation required. You may place the booster seat directly on the vehicle seat if there are no LATCH connectors. If there are LATCH connectors, the LATCH system on the booster can be used, but is is not required.
what is the difference between the Monterey 4DXT and the Cambria 2?
The 4DXT comes with an 11 position headrest, expandable seat back, aluminum alloy reinforced sides lined with EPS foam for side impact protection, and a stronger seat back designed for added strength. The Cambria 2 comes with a 6 position headrest and is lined with EPE foam for side impact protection. Both easily convert to a backless booster.
is there a top tether?
No, there is no top tether.