A 50hz transformer is required to use the Photon Stimulators in countries using 220/240 electrical currents.
As a rule-of-thumb, electronic or motorized appliances (using less than 50W) require transformer converters. Heating appliances (using more than 50 Watts) require transformer-less heating converters. If the wrong type of converter is used, something will burn up; using a heating converter with an electronic device will destroy the electronic device, a small transformer converter with a hair dryer will burn out the transformer. All models of Photon Stimulators use less than 50 Watts. Thus, they require a transformer converter – that is a converter that uses a transformer.