3M™ 'Betapure™ NT-T Series filter cartridges are 3M's latest advance in depth filtration technology. The all polypropylene filter is constructed using a design that utilizes flow enhancing filter media and an innovative flow pattern. The result is an absolute-rated filter with vastly superior on-stream life that provides more cost effective filtration than conventional melt-blown filter technologies. Betapure™ NT-T Series filter cartridges - the new leader in filtration performance.