Sealock manufactures heavy duty waterproof duffel bags for commercial fleets, marine operators, outfitters, and institutional buyers from factories in China and Vietnam. Buying duffels for an organisation is a different exercise from buying them for a store. The unit price matters less than the replacement cycle, the specification has to hold across every bag issued, and a failure in the field is an operational problem rather than a return. This sets out what "heavy duty" has to mean at commercial grade, and what a fleet specification should contain.