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Diono Monterey 4DXT 2-in-1 Latch Expandable Belt Positioning Booster Car Seat

Diono Monterey 4DXT 2-in-1 Latch Expandable Belt Positioning Booster Car Seat

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Product details
Official manufacturer description


We’ve taken the award-winning Monterey® booster seat and painstakingly engineered 15 upgrades to create the next generation of booster. Suitable from 40 - 120 lb (18 - 54 kg) or approx. 4 – 12 years. It includes automotive inspired fabrics that cover the entire booster seat back and breathable side panels to enhance airflow to keep your child cool on the move.

Extra deep aluminum reinforced sides provides 4 layers of enhanced side impact protection for their head, shoulders and torso.

It has 11 headrest positions and expandable side walls provides 69% increase in occupancy space as your child grows. Easily converts from a high back booster to a backless booster seat with wide contoured seat base and two retractable cup holders.

Equipped with LATCH connectors and front adjusters to securely connect the booster seat to your vehicle in seconds, enhancing safety and stability.


  • 15 upgrades from Monterey XT
  • 4 Layer side impact protection
  • Expandable Height and width
  • 2 Seats in 1
  • Quick and secure installation
Made in
Polypropylene, High Density Polyethylene, Metal
Polyester, Spandex
Product dimensions
‎16.1 in. D x 21.3 in. W x 27.2 in. H
Product weight
‎18.7 lbs
Head rest positions
Installation Type
Rigid Latch System
Model year
Recommended Age Range
4 to 12 years
Child Minimum Weight (Forward Facing)
40 lbs
Child Minimum Height (Forward Facing)
38 in.
Child Maximum Weight (Forward Facing)
120 lbs
Child Maximum Height (Forward Facing)
63 in.
Diono Monterey 4DXT 2-in-1 Latch Expandable Belt Positioning Booster Car Seat
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Top reviews
Would an expert recommend this for your baby?
Kristina Spencer
Kristina Spencer
Verified baby & toddler expert
Reviewed Sep 29, 2022

Fits kids from 40 - 120 lbs and converts from a high-back booster seat to a backless booster seat. The cup holders fold away when not being used and Diono is known for being a great fit for smaller spaces. It has excellent side impact protection and 11 different positions for the headrest to grow with your child. The fabric is machine washable and the seat has some plush, ergonomic padding for a comfortable ride for your child.