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Monterey® 5iST FixSafe®


FirstClass® Comfort, Ultimate SafePlus® Engineering. Convenient and Compact


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Monterey® 5iST FixSafe®

Unbox, unfold, install, adjust and go all in 2 minutes or less. One of a kind compact folding booster with SafePlus® easy-adjust backrest and headrest.


  • 8 Years One Booster - for your big kid from 18 - 54 kg. It's all you will ever need.
  • One-hand easy-adjust - SafePlus® 12-position headrest and backrest that grows up with your child. Engineered for safety and comfort with 8 layers of Side Impact Protection.
  • Built for comfort for every size - our backrest has deep padded cushioning.
  • One built-in removable cup holder - keeps your big kid's drink close at hand.
  • Our contoured premium soft fabrics - with layered foam padding that provide comfort and support can be easily removed for machine washing.
  • SafePlus® belt guides - easy access to seatbelt buckle help your big kid with self buckling - don't forget to check though!
  • Unbox, unfold, install, adjust and go - all in 2 minutes or less. Thanks to the SafePlus rigid LATCH connectors, all at a push of a button. Easy to move between cars, or to store at a push of the quick release latch button.
  • Engineered with our most side impact protection - our rigid shell is reinforced with 8 layers of high-impact aluminum and EPS energy absorbing foam, to protect the head, shoulders, and torso.
  • Folds to the size of a carry-on bag - great for storage in the trunk or at home. Perfect for trips by plane when you need a boost for your big kid.

Product Specs

  • Minimum User Weight: 18 kg / 40 lb
  • Maximum User Weight: 54 kg / 120 lb
  • Product Height: 63 cm / 24.8 in
  • Product Width: 43.2 cm / 17 in
  • Product Depth: 38 cm / 15 in
  • Seat Weight: 8.5 kg / 18.7 lb
  • Maximum User Height: 160 cm / 63 in
  • Number of Head Support Positions: 12
  • Product Height - Folded: 59.5 cm / 23.4 in
  • Product Width - Folded: 45.5 cm / 17.9 in
  • Product Depth - Folded: 19 cm / 7.5 in

Care & Maintenance

Covers: Machine wash cold, line dry. Shell and Components: Spot clean

Warranty Information

12 months standard warranty

Monterey® 5iST FixSafe™ Booster, Instruction Manual, Cup Holder, Carry Strap x2

Diono booster seats can be used for children weighing 40-120 lbs. (18-54 kg) and are 38-63 in. (96.5-160 cm) tall. Typically once a child reaches 5 years of age they are mature enough to ride in a booster seat.

Our booster seats fit 2 across in most cars. Each vehicle model is different and allows for various seating positions. Consumers should consult vehicle owners manual for appropriate car seat placement in their car that may fit more than 2 across.

Solana® has fabric cup holders. Solana® 2, Everett NXT, Cambria® 2, Monterey® XT, Monterey® 2XT, and Monterey® 4DXT have two retractable cup holders. Monterey® 5iST FixSafe® have a snap-in Monterey® cupholder.

Press the LATCH release button on the front of the booster. Attach the LATCH connectors to the vehicle’s lower anchors. Confirm the connector’s lock indicator changes from red to green. Push the seat backward until it touches the vehicle seat back.

Press the LATCH release button located on the front of the car seat and pull the car seat away from the vehicle backseat.

Yes, it can be used without the LATCH. They will need to use the shoulder seat belt to hold the seat in place when not in use to prevent it from becoming a flying object during a crash or sudden stop.

Locate the straps included with the car seat accessories. Attach the straps to the fabric loops on the back of the seat. Next adjust the straps for comfort before use.

Diono booster seats are not meant to be used on airplane. Boosters require a lap/shoulder belt and airplanes only have a lap belt.

All Diono booster seats have a life span of 8 years, starting from the date you purchase your seat. In the event the date of purchase cannot be determined then we use the date of manufacture.