Made in the form of multi-layered hollow cylinders of particular geometry, which are offered by us at the filtration market as depth filtering elements. New poroplasts ECOPLEN-F and ECOPLEN-PE in the form of porous films are marketed by us as low-selective membranes. In the course of filtration, such membranes retain particles mainly on their surface (screen retention mechanism); however, due to sufficiently wide distribution of pore sizes, particles can be also retained in the volume (depth retention mechanism). Poroplasts can be used as aerators, pressure compensators, breathing partitions, porous media, and for other purposes connected with permeability of materials.