Conforms to EN 143:2000/A1 and EN14387. P3 R particle filters protect against a range of dust particulates. Only suitable for twin filtered masks. This includes the X-plore 3300 and 3500 half masks and also the X-plore 5500 full face mask. The filters are packaged in a pair which make them both economical and protects unused filters. The P3 filters are 99.95% efficient in filtering out particles.