S K Industries manufactures Primary Stage Coarse or Pre Filter. S K Industries is an ISO 9001: 2000 certified company. The Primary Stage Coarse or Pre Filter available in grades ranging from G2 to G4 with various constructions like Z Type, Microvee Type and Flat Type. The Coarse or Pre Filter is used to arrest large dust particles of size down to 10 microns and is suitable for any air handling applications.