Capsulated single-phase Vario® transformer designed and tested according to VDE0570. Designed as a torodial autotransformer. RV-21 is a table model, fixed installation. Degree of protection IP20. The Noratel Vario® transformer is an optimal solution when continuous control of voltage and current is preferable. The construction ensures a clean sine voltage and no radio interference or additional harmonics are generated. In addition to standard types, Vario® variable transformers are supplied strictly on customer request.