Pack of 5 filter bags 22cm x 13cm Ideal for having crystal clear water our filters are made of polyester for optimal filtration and lifespan The fineness of filtration is like the original one: 6, 15 and 30 microns They are easily installed between the two retaining rings They can be cleaned with a jet of water or in the washing machine (30 degrees without detergent product) 6, 15 or 30 microns How to choose The fineness of filtration is expressed in microns. The smaller the value, the finer the filtration. To better understand, a human hair measures between 50 and 100 microns in diameter approximately. 6 microns allows very fine filtration. It filters fresh water whose external pollution is very low. You can use the 6 micron filter bag when your pool traffic is relatively low. It retains impurities for clear and limpid water and thus offers perfectly crystalline water. This bag requires regular maintenance and cleaning. 15 microns recommended in season under normal conditions of use of the swimming pool. It thus provides you with balanced pool water throughout the summer. This is the most standard filtration and the most widespread choice. 30 microns ideal at the start of the season to get your pool back up and running, when winterizing and during prolonged absences. It can also be used for pool water that is charged, unbalanced or even for the recovery of green water. This pouch requires less frequent maintenance and cleaning than other pouches.