Their base is metal or hard cardboard and they are mainly manufactured in Z-line form 48 or 98 mm thick (air speed 2.5 m/sec), but also straight form in thicknesses usually 10 - 20 mm (air speed 1.5 m/sec).

Class G2-G3-G4 Synthetic filters

They are used as a first or second filtration stage to retain larger dust particles and are widely used in small and large air conditioning units. They allow the passage of a large amount of air (especially the Z-Line type), have a low initial pressure drop and a long service life.

In addition to the standard types, they are manufactured in any dimension required.