These unique, long-life prefilters are designed by MSA for respirator users. Their exclusive 'Hawley' design features deep circular pleats which extend the amount of filter loading on the filters, allowing respirator users to continue their spraying jobsor projects without the need to continually stop to replace the pre-filter. For Use With: 294.9485 Replacement Cartridges, which fit on all MSA Safety Works twin cartridge respirators. This respirator is approved by NIOSH under the NIOSH 42 CFR 84 respirator certification regulations. This Paint & Pesticide respirator is approved to the R95/OV category. Applications: Painting/spray painting (except urethane paints), Stripping paint/lacquer, Applying pesticide/fertilizer.