The filter and valve replacement pack is for use in an FB-1 Respro® Mask. The filter screens firefighters from dust in circumstances where breathing apparatus would not normally be used, but where it is reasonable to suspect that the surrounding air supply could be contaminated with certain types of invisible dust particulates.

The filters screens out respirable particulates (PM1’s) such as allergenic and non allergenic dusts, carbonaceous material and pollen. The two Techno™ exhalation valves release CO₂, heat and water vapour from the filter material thus leading to comfortable breathing.