NB0050PPS2C
SURPLUS NEW 3M NB0050PPS2C NB Series Filter Bag 50 micron (Box of 50) – Air
The 1/4 in width is what makes it fit into those narrow channels.
3M NB0050PPS2C NB Series Filter Bag 50 micron (Box of 50)
The ABB name is common in water treatment and mining operations.