SUMMIT-X UltraLight Packable Backpack 15L

Waterfly SUMMIT-X UltraLight Packable Backpack 15L is a 15L, 0.31kg0.7lb travel backpack measuring 41.9×27.9×11.9cm16.5×11×4.5in. It fits the carry-on size limit of 36 of 36 major airlines and the personal-item limit of 9 of 26. Under the seat, its 41.9cm16.5in side is over the 40cm15.7in limit at 12 of the 17 airlines it misses. Specs from waterflyshop.com, checked October 2026.

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Volume: 15Lfixed size
Weight: 0.31kg0.7lb0.7lb0.31kg
Carry-on: 36/36airlines fit it
Personal item: 9/26under-seat limits

Dimensions: 41.9×27.9×11.9cm16.5×11×4.5in 16.5×11×4.5in41.9×27.9×11.9cm
Price: $34.99 as of October 2026
Laptop: n/a
Opening: Zippered main compartment
Warranty: 10 years 10-year limited warranty for registered members buying direct; guests 3 years.
Compartments: n/a
Bottle pockets: 2

Water-resistant
Sternum strap

Material: Tear-resistant, water-repellent nylon, polyester lining

Folds to a 7.87 x 6.3 x 2.16 in pouch
Middle pocket sized for iPad mini or iPad Air
Built-in emergency whistle and trekking pole loop

Last checked: 2026-10. Prices and specs may have changed.

Does the Waterfly SUMMIT-X UltraLight Packable Backpack 15L fit airline carry-on limits?

Draw against

Fits as a cabin bagFits as a cabin bag on Ryanair. cabin bag 55×40×20cm21.5×15.5×8in · under the seat 40×30×20cm15.5×12×8in. Bag in cminches, turned to fit.

Flag as a tight fit undercm spare

Airline	Carry-on	Personal item	Cabin-bag weight
Air Arabia	FitsFits	Too bigToo big	6.7kg to pack (of 7kg)14.8lb to pack (of 15.4lb)
Air CanadaCabin bag not on every fare	FitsFits	Tight fit (1.1cm spare)Tight fit (0.4in spare)	No published limitNo published limit
Air FranceCabin bag not on every fare	FitsFits	Too bigToo big	11.7kg to pack (of 12kg shared with personal item)25.8lb to pack (of 26.5lb shared with personal item)
Air India	FitsFits	No published limit	6.7kg to pack (of 7kg)14.8lb to pack (of 15.4lb)
AirAsia	FitsFits	Too bigToo big	6.7kg to pack (of 7kg shared with personal item)14.8lb to pack (of 15.4lb shared with personal item)
Alaska Airlines	FitsFits	No published limit	No published limitNo published limit
Allegiant AirCabin bag not on every fare	FitsFits	FitsFits	No published limitNo published limit
American Airlines	FitsFits	FitsFits	No published limitNo published limit
ANA (All Nippon Airways)	FitsFits	Too bigToo big	9.7kg to pack (of 10kg shared with personal item)21.4lb to pack (of 22lb shared with personal item)
AviancaCabin bag not on every fare	FitsFits	No published limit	9.7kg to pack (of 10kg)21.4lb to pack (of 22lb)
British Airways	FitsFits	FitsFits	No published limitNo published limit
Cebu Pacific	FitsFits	Too bigToo big	9.7kg to pack (of 10kg shared with personal item)21.4lb to pack (of 22lb shared with personal item)
Delta Air Lines	FitsFits	No published limit	No published limitNo published limit
easyJetCabin bag not on every fare	FitsFits	FitsFits	14.7kg to pack (of 15kg)32.4lb to pack (of 33.1lb)
Emirates	FitsFits	No published limit	6.7kg to pack (of 7kg)14.8lb to pack (of 15.4lb)
Frontier AirlinesCabin bag not on every fare	FitsFits	FitsFits	15.6kg to pack (of 15.9kg)34.4lb to pack (of 35.1lb)
Gol Linhas Aereas	FitsFits	No published limit	9.7kg to pack (of 10kg)21.4lb to pack (of 22lb)
IndiGo	FitsFits	No published limit	6.7kg to pack (of 7kg)14.8lb to pack (of 15.4lb)
JetBlue Airways	FitsFits	Tight fit (1.1cm spare)Tight fit (0.4in spare)	No published limitNo published limit
KLMCabin bag not on every fare	FitsFits	Too bigToo big	11.7kg to pack (of 12kg shared with personal item)25.8lb to pack (of 26.5lb shared with personal item)
LATAM Airlines	FitsFits	FitsFits	11.7kg to pack (of 12kg)25.8lb to pack (of 26.5lb)
LufthansaCabin bag not on every fare	FitsFits	Too bigToo big	7.7kg to pack (of 8kg)17lb to pack (of 17.6lb)
Norwegian Air ShuttleCabin bag not on every fare	FitsFits	Too bigToo big	9.7kg to pack (of 10kg shared with personal item)21.4lb to pack (of 22lb shared with personal item)
Qantas	FitsFits	No published limit	6.7kg to pack (of 7kg shared with personal item)14.8lb to pack (of 15.4lb shared with personal item)
Qatar Airways	FitsFits	No published limit	6.7kg to pack (of 7kg)14.8lb to pack (of 15.4lb)
RyanairCabin bag not on every fare	FitsFits	Too bigToo big	9.7kg to pack (of 10kg)21.4lb to pack (of 22lb)
SAS	FitsFits	Too bigToo big	7.7kg to pack (of 8kg)17lb to pack (of 17.6lb)
Singapore Airlines	FitsFits	Too bigToo big	6.7kg to pack (of 7kg)14.8lb to pack (of 15.4lb)
Southwest Airlines	FitsFits	No published limit	No published limitNo published limit
Turkish Airlines	FitsFits	Too bigToo big	7.7kg to pack (of 8kg)17lb to pack (of 17.6lb)
United AirlinesCabin bag not on every fare	FitsFits	Too bigToo big	No published limitNo published limit
Vietjet Air	FitsFits	Too bigToo big	6.7kg to pack (of 7kg shared with personal item)14.8lb to pack (of 15.4lb shared with personal item)
VolarisCabin bag not on every fare	FitsFits	FitsFits	9.7kg to pack (of 10kg)21.4lb to pack (of 22lb)
VuelingCabin bag not on every fare	FitsFits	Too bigToo big	9.7kg to pack (of 10kg)21.4lb to pack (of 22lb)
WestJetCabin bag not on every fare	FitsFits	Too bigToo big	No published limitNo published limit
Wizz AirCabin bag not on every fare	FitsFits	Too bigToo big	9.7kg to pack (of 10kg)21.4lb to pack (of 22lb)

Compared in any orientation against each airline's published size limit. A tight fit has under 2cm to spare, so a packed soft bag may not pass a sizer. Set it to 0 to turn the warning off. Weight is what the airline allows in the cabin minus this bag's empty 0.31kg0.7lb. Limits and sources. Own a different bag? Check it against every airline.