Pre-filters in rolls of dimensions 2Χ20m fabricated by polyester fibers. The thickness of the rolled pre-filters is varies between 5mm to 20mm depending on the filtration demand. The classes of the filters in rolls are G2, G3 and G4 and as a result they have the ability to restrain the 75% to 90% of the air particles (gravimetric efficiency). They have applications in industrial as well as in civil conditioning plants. They are appropriate for the separation of particulates with medium to high granulometry. There is the possibility the rolls to be cut in smaller dimensions according to the customer’s needs.