Frecuency converter

I need guarantee and quality articles to work in my eletricity workshop . About that I elect the products of Shandy.
They have an extensive catalogue of articles and excellent prices. You can find different models of ac dc converter of frecuency .
A frecuency converter is very useful but is necessary that it is very good quality. To be calm in my work I bought an ac dc frecuency converter of Shandy.
The most effective solution.