Examples of high-value, fragile or perishable items for which United is not liable (in the case of travel within the United States) or for which United’s liability may be limited (in the case of most international travel) include, but are not limited to:
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• Items checked in corrugated/cardboard boxes, including cardboard boxes provided by United, except for items that otherwise would be suitable for transportation without the cardboard box (e.g., bicycle, garment bag)

During an excess baggage embargo, when no excess baggage is accepted: one box, instead of one free bag; maximum 50 pounds (23 kg) and 62 linear inches (158 cm) (total length + width + height) will be accepted free of charge. Exception: one box is accepted on ExpressJet Airlines, Inc. doing business as United Express® with destinations to the Caribbean, Central America and Mexico, instead of one bag; maximum 50 pounds and 42 linear inches (107 cm).