The PP5-20BB cartridge is used in a 20BB main filter to purify water from insoluble impurities (larger than 5 micrometers). It is made in Russia.
The PP 5-20BB cartridge is made of expanded polypropylene and is designed for the mechanical purification of water from rust, dirt, sand, and other insoluble impurities larger than 5 micrometers. It is not meant for restoration and should be replaced with a new one after its service life ends