Material			Length		*Micron rating	Treatment
N-	P	Polypropylene	-P-	250	-L-	1	N	Normal
	PE	Polyethylene		500		3	Z	Zeta potential
	PN	Polyethylene & nylon		750		5
	R	Rayon		1000		10
						25
						50
						75
						100
						200

*nominal removal efficiency
Example: NPP-250L-5-N polypropylene cover prefilter 250mmL, 5micron, normal treatment