Diono Monterey 2XT Latch 2 in 1 High Back Booster - Flexible Fit

In this review the Diono Monterey 2XT Latch 2 in 1 High Back Booster is evaluated for parents who need a long-lasting, adaptable booster as their child grows. The bottom line: this seat is best for families seeking one lightweight, portable booster that converts from high back to backless and offers a surprisingly wide range of adjustment to fit children roughly 4 to 12 years old. The reviewer found the seats expandable sides and one-handed headrest adjustment to be the single biggest reason to buy for changing fit over multiple years.

Key Features

• Adjustable headrest: Eleven headrest positions let caregivers raise the head support up to 6.5 in to keep the belt line and head properly aligned as a child grows.
• Expandable width: A simple dial on the back widens the seat sides so the booster can expand up to about 20 in for broader shoulders and more comfortable rides.
• Two modes in one: Converts easily from a high back booster to a backless booster for use from approximately 40 to 120 lb, extending the service life of the seat.
• Lightweight portability: The Monterey 2XT is designed to be relatively easy to move between vehicles while still providing substantial side protection and support.
• Side impact protection: Built-in side protection gives additional coverage for head and torso compared with basic backless boosters.

Who It's For

The Monterey 2XT is aimed at parents of school-age children who need a single seat that adapts over several years, roughly ages 4 to 12 and 40 to 120 lb. It suits families who value adjustability and portability and who want the option to switch to a backless booster when the child is ready.

Parents who want a narrow, ultra-compact seat for very small cars or those who need an infant-to-booster solution should look elsewhere, since this seat starts at the higher weight range and focuses on adjustable booster fit rather than infant or convertible seat features.

Pros & Cons

Pros

• Long usable range in one seat with a clear conversion from high back to backless booster.
• Wide adjustability with 11 headrest positions and a width dial provides a tailored fit over years.
• Relatively lightweight and portable compared with many full-size boosters, making transfers between cars easier.

Cons

• Does not cover infant needs; its lower limit around 40 lb means families need a separate forward-facing seat earlier on.
• Fewer recline options than larger multi-mode seats, limited to two recline positions.

Specifications

Brand	Diono
Model	Monterey 2XT Latch 2 in 1 High Back Booster
Use range	Approx. 40 - 120 lb (about 4 - 12 years)
Headrest positions	11 positions, adjusts up to 6.5 in
Width adjustment	Dial expands seat width up to about 20 in
Recline	2 recline positions
Conversion	High back booster to backless booster

Our Verdict

The Diono Monterey 2XT is a practical choice for parents who want a single, adaptable booster that grows with their child and is easy to move between vehicles. Its expandable width, multi-position headrest and backless conversion offer clear long-term value for families whose children meet the 40 to 120 lb range and who prioritize fit and portability over infant compatibility.

Frequently Asked Questions

What age and weight is this booster appropriate for?
The Monterey 2XT is intended for children approximately 4 to 12 years old and from about 40 to 120 lb.

Can the seat be used without the high back?
Yes, it converts to a backless booster to accommodate older children and extend the seats usable life.

How do you adjust the width and headrest?
The seat uses a rear dial to expand the width up to around 20 in and a one-handed headrest control to raise the headrest up to 6.5 in across 11 positions.