Monofilament (MO) filter bags are available special woven mesh filters, Nylon Mono filament, Polyester Multifilament, Polypropylene Monofilament.These rugged materials are precisely woven and heat stabilized to produce fixed and constant apertures. As a result, MO bags have absolute filtration ratings from 101250 m. mu making them ideally suited for hard particle removal and retension. In many cases, they can be washed multiple times for economic use.