These are ACTIVATED CARBON IMPREGNATED bag filters.  They are commonly used as an odour control in commercial catering extraction systems.  Must be used with a pre-filter.

Header frame:  Rolled galvanised steel with safety edge.

Media:  Synthetic media 100% impregnated with activated  carbon – high grade powder.

Initial resistance:  25 p.a.

Final recommended resistance:  100 p.a.