Within this category, there are Earth Leakage add-on Blocks of the three most large management staff for webdesign companies manufacturing this product that is, Bticino,Siemens, and Abb. The Differential Lock is not a differential pure with 2-pole protected, but that must be coupled obligatorily to a circuit breaker. In this category you will find the blocks differential Bticino,Siemens, Abb and a 2 modules din.