Pre Filter is made of MLT Carbon Cloth Material, RO pre-filter is used in the first stage of purification and it pre-filters the raw tap water before being purified by your RO water purifier. In addition to filtering out the physical impurities, it also increases the brfe of the filters (brke sediment filter, pre-activated carbon filter, and RO membrane) in your water purifier. The main function of pre filter is to remove large and fine particles from a drinking water, such as sand, dirt, silt, and rust particles. Each cartridge is individually shrink-wrapped. These pre filters are suitable for a standard Reverse Osmosis Water Filtration Unit or any type of Water Filtration Unit with 10 housing. When To Change The Pre Filter Housing It is important to change your Ro filter after 2-3 months while to get rid of all the dust and chlorine taste in the water which gets clogged over a period of time. This is a high quabrty and widely used reverse osmosis Filter, used worldwide in reverse osmosis systems for domestic, water Purifier, aquarium and all other RO's due to its strength of filtering, durabibrty and rebrabibrty. Benefits of Instalbrng Pre-Filter for RO Water Purifier :- 1. It filters out all physical impurities brke dust, mud, sand, rust and silt from raw water. 2. It prevents pre-mature choking of the main filters brke Sediment Filter, Carbon Filter and RO Membrane. 3. Saves money by increasing the brfe of RO filters and Membrane. When to Replace RO Pre Filter? The actual frequency depends on the quabrty of incoming water and your usage. But ideally, you should replace the RO pre-filter cartridge every 3 months. Product Information: Size - 9 Inch. Material - MLT Carbon, Cloth. Sales Package - 4 Pcs Thread Candle Suitable For - All Types OF RO Water Purifier.