3M™ SERIES NB POLYPROPYLENE & POLYESTER BAG FILTERS LEVERAGE 3M’S FILTRATION EXPERIENCE AND MANUFACTURING EXPERTISE TO PROVIDE COST EFFECTIVE SOLUTIONS FOR APPLICATIONS WHERE NOMINALLY RATED BAG FILTRATION IS APPROPRIATE. 3M SERIES NB BAGS ARE OFFERED IN SIZE #1 AND #2 CONFIGURATIONS IN GRADES FROM 1 TO 200 MICRONS AND FIT INTO STANDARD BAG FILTER BASKETS AND HOUSINGS.