Our magnetic filter MF-D DRYL is designed to work with systems where constant liquid cleaning from large magnetic and non - magnetic particles is essential. It also acts as an air-vent which, in connection with its internal filter basket, works for better central heating system performance, improves energy efficiency and extends the life of your boiler and whole central heating system. Moreover, it stops tiny magnetic shards from being spread into the whole system, something which is directly responsible for causing rust and corrosion. MF-D also removes black ferrous oxide or sludge, which can seriously reduce boiler's efficiency by limiting heat transfer or blocking pipes. This product can be used as a main filter through which 100% liquid is run. The magnetic filter is made of black/mild steel but the whole internal areaand parts, with the exception of the filter basket and magnet, are covered by a layer of zinc, thus helping to prevent corrosion. While cleaning, there is no need to remove the magnetic parts from the stainless-steel, non magnetic basket, saving time and keeping your environment clean.