All CLUSE products comply with the strictest legislation and regulations regarding chemical composition set by the European Union and the United States of America. This means that the materials used are not necessarily nickel free. However the materials which do contain nickel, are composed/constructed in such a way that the release of nickel is restricted to the absolute minimum.
The legal limit of release is low enough to be sure that the majority of people with a nickel-allergy will not react to it.