The cartridges are thermally bonded to provide integral joints between the pliable end caps and rigid centre core for added strength and long service life. Pleated cartridges are particularly useful for low pressure applications such as domestic supplies using header tanks or roof water. These filters are our premium product and available in 1 micron and 20 micron. Description Polypleated Sediment Cartridges - Maximum flow rate of 35lpm,For finer sediment removal, commonly used in 1st and 2nd stage of filtration for the removal of: Rust Sand Silt Algae Cryptosporidium cysts (>99% efficient for 1 micron cartridge) Material is food grade polypropylene with no chemical residue or loose fibre * These filters are our premium product and available in 1 micron and 20 micron.