Some models list a volume in litres, while others describe an approximate number of cans. Neither tells you whether your particular lunch box will fit. Compare the internal dimensions when provided and allow room for cooling packs.
Compare the practical details
A tall drinks container needs a different shape from a flat food container. For family outings, separate drinks and delicate food when practical. Do not assume an advertised can count includes extra ice or accessories.
Prepare the enquiry
Ask for clarification when a listing does not provide the measurement you need. Choose a bag you can carry comfortably once loaded, rather than simply buying the largest one.