The Stroom Master® is our only product which is designed to filter AC EMF(dirty electricity) pollution generated by voltage transients and harmonics present in power lines. The Stroom Master® is also Equipped with our patented SPIRO® technology, it contains a quantity of SPIRO material that is 3 times stronger than that of the SPIRO CARD. This creates a joint effect that is capable of filtering noise within the electrical wiring line, while naturally polarizing the fields surrounding the electrical wiring and the area where the filter is attached (up to 8 ft radius). The Stroom Master® is a 2-in-1 filter that we recommend you place every 200 sq ft or in each room of your home. Although it does contain SPIRO material, it is mostly designed for dirty electricity so we recommend using a SPIRO DISC as well in order to keep your home completely electrosmog free. This filter has been found to not affect the performance of the devices it is used with; on the contrary, laboratory tests have shown that it is fully compatible with them, optimizes their operation, and lengthens their useful life.