The one that is provided to you free of charge by the seller of the device.

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Digitec (or any other Swiss retailer) is obliged to supply electrical appliances with a Swiss plug. If the appliance is supplied with a foreign plug, a suitable replacement cable should be supplied if the mains cable is pluggable or, alternatively, if the mains cable is permanently connected, a suitable adapter should be supplied.

If the appliance is delivered without a suitable plug, complain to the customer service and insist on a cable or an adapter, free of charge.

Info Digitec --> https://helpcenter.digitec.ch/hc...
Point 1 --> https://www.esti.admin.ch/de...