These filters are designed on the base of Concentration of fluoride of the raw water sources. It  removes also  iron, turbidity and other insoluble particles and deliver safe drinking water  . The Vessels are made of FRP Pentair/equivalent and the filter beds are made of Fluoride removal media .The use of those filters are before RO systems and other water treatment plants to protect the main filter or processes sing to the other treatment plants or boiler.