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Nuna LUMN

The Nuna LUMN forward-faces up to 65 lb, is 18.3 in wide, and weighs 26.2 lb, per Nuna.

  • 65 lbHarness to
  • 110 lbBooster to
  • 26.2 lbSeat weight
  • 18.25 inWidth
See it on Nuna's site

When does it expire?

Follow Nuna

All harness-to-booster car seats

LUMN: key facts

  • The Nuna LUMN forward-faces with a harness from 30 to 65 lb and 34 to 49 in tall; works as a booster from 40 to 110 lb and 43 to 57 in tall, per Nuna.
  • It installs with lower anchor belt and tether (harness mode), vehicle belt and tether (harness mode) or vehicle belt without lower anchors (booster mode).
  • Nuna says it expires 10 years after the date of manufacture.
  • Nuna lists it as certified for aircraft ("This restraint is certified for use in aircraft. The child restraint is NOT certified for aircraft use when used as a booster.").
  • It's 18.3 in wide at the widest point and weighs 26.2 lb.

From Nuna's manual and published specs. Always follow the limits on your seat's labels.

How the LUMN stacks up

Against the 22 harness-to-booster car seats we track. The shaded band is where the middle half of them fall; the dot is this one.

Expiration10 years

Within the typical range for harness-to-booster car seats (8 years to 10 years).

This one
6 yearsmiddle 10 years10 years
Forward-facing limit65 lbHighest forward-facing limit of 22 harness-to-booster car seats

The same as most harness-to-booster car seats (65 lb).

This one
40 lbmiddle 65 lb65 lb
Width18.3 in4th narrowest of 11

Within the typical range for harness-to-booster car seats (18.3 in to 19.4 in).

This one
17.5 inmiddle 19 in21.9 in
Weight26.2 lb15th lightest of 15

Above the typical range for harness-to-booster car seats (16 lb to 25 lb).

This one
9.1 lbmiddle 23 lb26.2 lb

What sets the LUMN apart

Measured against the 22 harness-to-booster car seats we compare, from each maker's published specs.

  • Highest seat weightof the 15 harness-to-booster car seats that list it: 26.2 lb
  • Highest recline positionsof the 7 harness-to-booster car seats that list it: 9
  • Width: 18.3 inin the middle half of the 11 harness-to-booster car seats that publish it (18.3 in to 19.4 in)
  • Weight: 26.2 lbabove the middle half of the 15 harness-to-booster car seats that publish it (16 lb to 25 lb)

Next to its closest matches

Flying with the LUMN

Nuna's label: “This restraint is certified for use in aircraft. The child restraint is NOT certified for aircraft use when used as a booster.” It is 18.25 in wide at its widest point.

What airlines say about car seats:

  • American: “Each ticketed customer is allowed 1 stroller and 1 car seat to be checked free of charge” “If an unoccupied, adjoining seat is not available, the gate agent will check the safety seat to your final destination.” Source
  • Alaska: “We will transport your child's car seat and stroller free of charge as checked baggage.” Source
  • JetBlue: “Checking a child safety seat will not count towards your checked baggage allowance and there is no fee assessed” Source
  • Spirit: “One (1) car seat will be accepted per child as checked baggage at no charge.” Source
  • Frontier: “strollers and car seats can be checked for free.” Source
  • Allegiant: “There is no charge for checking or gate checking one car seat per fare-paying passenger.” Source
  • Breeze: “Child seats may be carried on board the aircraft if a seat has been purchased for the Infant or Child” Source

Quoted from each airline's page as of 2026-11-02.

Listed features

  • Maker lists 10 headrest positions and 9 recline positions (with top tether)
  • Maker states 'Fire-retardant free'
  • Maker lists FAA certification in harness mode

Worth checking

  • Not certified for aircraft use in booster mode per manual

Where to buy the LUMN

Prices and availability change. We may earn a commission from some links.

good to know
  • Check for recalls: Search the agency's recall list with the model number and date code from the label: NHTSA recall search.
  • Car seat use and installation: see NHTSA's car seat page, which also lists free car seat inspection by certified technicians. Check the label and the maker's instructions, and ask your pediatrician about your child.

Full specs

Nuna LUMN
TypeHarness-to-booster
Forward-facing weight30–65 lb
Forward-facing height34–49 in
Booster weight40–110 lb
Booster height43–57 in
Seat weight26.2 lb
Width18.25 in
Newborn insertBody insert: 'The body insert MUST be used for a child up to 40lbs (18 kg).' Seat insert used only from 30 lbs up to 65 lbs in harness mode; remove in booster mode.
Installationlower anchor belt and tether (harness mode), vehicle belt and tether (harness mode), vehicle belt without lower anchors (booster mode)
Load legNo
Anti-rebound barNo
RotatesNo
Harness heights10
Recline positions9
Aircraft labelCertified for aircraft, per the maker
No added flame retardantsYes
Expires after10 years

Compare the LUMN with

How each closest rival differs from the LUMN, from the makers' specs.

Ask the meadow

LUMN: questions answered

From Nuna's published specs, last checked 2026-11-06.

Will the Nuna LUMN fit three across or in a small car?

It's narrower than 64% of the harness-to-booster seats we track, at 18.3 in. The narrowest is the Chicco MyFit ClearTex Harness + Booster at 17.5 in. Fit depends on your vehicle; check each seat's manual and your vehicle manual. Car seat use and installation: see NHTSA's car seat page, which also lists free car seat inspection by certified technicians. Check the label and the maker's instructions, and ask your pediatrician about your child.

Can you bring the Nuna LUMN on a plane?

Yes, Nuna lists it as certified for aircraft; look for the red-lettered label that says so. The FAA asks that a car seat go in a window seat so it doesn't block the aisle, and the crew will look for that label. It weighs 26.2 lb to carry through the airport.

LUMN or Defender 360° MAX 3-in-1 Deluxe: what's different?

By the makers' specs, the LUMN has no added flame retardants (maker's claim). See every spec side by side.

Is it OK to buy a used LUMN?

NHTSA publishes guidance on used car seats on its car seat page. Nuna lists a lifespan of 10 years from manufacture for this model. Check the label and the maker's instructions, and ask your pediatrician about your child.

Still wondering? Write to us at hello@cribpicks.com and we'll look it up.

More harness-to-booster car seats

Where these specs come from

Last checked 2026-11-06. Spot something wrong? Tell us. Read our editorial and safety policy and corrections.