Nilfisk GB933 and GB1033 Ind Vacuum Cleaner Gore-Tex Main Filter OBSOLETE
These filters are now obsolete.
I can say PN 61908300 is made from the same material. HOWEVER, THE TOP DIAMETER IS ABOUT 75 mm LESS THAN WHAT'S REQUIRED. See the second picture for the comparison in the tops.
SIMILAR to Picture, but the one photographed is for the Nilfisk GM626 Industrial Vacuum Cleaner PN 61908300.
Fitting these filters is quite difficult if the person fitting it, hasn't done one before.