Do the participants need to be equipped with physical devices?

If the product under testing needs to be shipped to the participants, the coordination of the delivery, the delivery times to the various destinations, and any potential delays due to customs checks, have to be taken into account. We have also run into delays when the plugs of the devices being shipped were local to the country manufacturing them, while the participants they were being shipped to lived in countries with other standards for plugs and sockets. Either the participants are then asked to buy adapters, or the study sponsor sends them out to all participants.