(45)For a period of one year, or for a period of two years if Member States choose to apply a two-year period, the consumer should only need to prove that the good is not in conformity, without also needing to prove that the lack of conformity actually existed at the relevant time for establishing conformity. In order to rebut the consumer's claim, the seller would need to prove that the lack of conformity did not exist at that time. In addition, in some cases the presumption that the lack of conformity existed at the relevant time for establishing conformity could be incompatible with the nature of the goods or the nature of the lack of conformity. The former could be the case with goods that by nature deteriorate, such as perishable products, for example flowers, or goods which are only intended for a single use. An example of the latter would be a lack of conformity, which can only be a result of an action by the consumer or of an evident external cause which occurred after the goods were delivered to the consumer. In the case of goods with digital elements where the contract provides for continuous supply of the digital content or digital service, the consumer should not have to prove that the digital content or digital service was not in conformity during the respective period of time for establishing conformity. In order to rebut the consumer's claim, the seller would need to prove that the digital content or digital service was in conformity during that period.