3Mâ„¢ Particulate Respirator 9312 P1 is a P1 filter in unique 3 panel flat fold design with 3Mâ„¢ Cool Flowâ„¢ valve for greater comfort. For mechanically generated particles e.g. grinding, sanding, crushing and sawing. Cool Flowâ„¢ valve prevents heat and moisture build up, making breathing easier. Individually wrapped. 10 per box.