P100 HALF MASK RESPIRATORS & REPLACEMENT FILTERS Klein Tools expands its Personal Protective Equipment lineup with the addition of P100 Half-Mask Respirators and Replacement Filters. These respirators offer maximum particle protection in rough and dirty environments such as jobsites, construction and industrial sites, and facility maintenance operations. The P100 Safety mask, together with the P100 filters, give protection against hazardous and toxic solid and liquid particles: dust, metal fumes and mist.