These filter bags are for heavy dirt load application.With 3 times the surface area of similar of sized bags,it will increase the amount of contaminant held, and extend the time between change-out. Rated 1-110 microns at 95% effciency. Top By welding each bag seam together this exclusive S&C positive heat-sealing process eliminates all needle holes that allow impurities to escape. S&C indusrty standard,panted, Poluloc one piece molded top provide a more positive seal than sewn ring top bags,and features built-in handles for faster,easier installation and removal. Top S&C industry standard, patended, polyloc one-piece molded top provides a more positive seal than sewn ring top bags, and features built-in handles for faster, easier installation and removal.