High-Flow Felt Filter Bags - Initial pressure drop less than 0.5 psi for max. rated flow at 68°F Pkg. of 20Single-layer bags are ideal for high flow rates. Handle and ring sewn in at top allow easy filter changes. Heat-welded seams. Glazed finish for low fiber migration, good depth filtration, and good solids-holding capacity. For use with alkalies, organic solvents, petroleum and vegetable oils, and organic and mineral acids.