Needle punched fabric along with multiple layers of different media like Spunbonded fabric, Nylon Mesh, Microfiber melt-blown fabric These filter bags give extremely good filtration rating at a high flow rate. This bag also gives Microfiber materials that provide high efficiencies at low micron ratings. The optional addition of a needle punched felt layer provides a pre-filter zone and results in extended life. This multilayer technology option results in a true graded density material with high-performance levels.