Big Kid

Car Seats
for children 40-110 lbs. / 4 years and up


Big Kid Sport Highback 2-in-1 Belt-Positioning Booster Car Seat (Mia)

Big Kid Sport Highback 2-in-1 Belt-Positioning Booster Car Seat (Mia)


Sporty patterns adorn the cushioned seat and backrest, making this Big Kid a hot rod among booster seats. An elevated seat, six height settings, and upper belt guides help you ensure your vehicle's seat belt is properly positioned across your child's chest and legs. The Big Kid Sport also converts to a backless booster allowing you to keep your growing child safe longer.


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Item No. 31911571

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Additional Information

Go big or go home...

Perfect for your growing child, this seat belt booster combines the peace of mind parents require, with colorful options your child will love.

Child Specs (40-110lbs.)


  • Weight: 30 - 110 lbs. (13.6 - 49.8 kg.)
  • Height: 38 - 57 in. (97 - 145 cm.)
  • Age: amp-bk-age
  • Fit: Child’s ears are below top of child restraint headrest.


  • Weight: amp-bk-nb-weight
  • Height: amp-bk-nb-height
  • Age: amp-bk-age


  • Age: At least four years of age

Product & Shipping Specs

  • Package Width: 16.5
  • Package Weight: 8.07
  • Package Depth: 11.25
  • Package Height: 19.25

Safety Testing

At Evenflo, we continue to go above and beyond government standards to provide car seats that are tested at 2X the Federal Crash Test Standard.

  • Side Impact Tested: Meets or exceeds all applicable federal safety standards and Evenflo’s side impact standards.
  • Designed and tested for structural integrity at energy levels approximately 2X the federal crash test standard.
  • FMVSS 213: Federal Motor Vehicle Safety Standards for Child Restraint Systems
  • FMVSS 302: Federal Motor Vehicle Safety Standards for Flammability of Interior Materials
  • CMVSS 302: Canada Motor Vehicle Safety Standard
  • CMVSS 213: Canada Motor Vehicle Safety Standard
  • Certified For Use In Aircraft: When used with the internal 5-point harness this restraint meets FAA Inversion requirements for airplane use.
  • Evenflo Temperature Testing: All current Evenflo car seats are tested for product integrity at both high and low temperatures.

Use & Care

Read all instructions and warnings on the product, product labels, and instruction manuals before use. Consult your vehicle owner’s manual to determine proper placement of child restraint in your vehicle and familiarize yourself with your vehicle’s components.

Browse Instruction Manuals »

Cleaning Instructions
  • DO NOT lubricate or immerse in water any part of this child restraint, unless rinsing is permitted
  • Plastic and metal parts may be wiped clean with mild soap and water and dried with a soft cloth. Do not use abrasive cleaners or solvents.
  • Take care not to damage any labels.
  • The harness can be wiped clean with mild soap and water. Allow harness to air dry.
  • Machine wash the seat pad separately in cold water, delicate cycle. Tumble dry 10 to 15 minutes on low heat.
  • Periodically inspect and clean the restraint's crotch buckle of food, liquids, and other debris to ensure proper latching. Place the buckle in a cup of warm water and gently agitate the buckle back and forth. Press the red button several times while the buckle is in the water. Do not submerge the harness strap. To avoid damage to the buckle, do not clean the buckle with soap or detergents and do not use a lubricant.