Particle filter SR 510 P3 R that protects against all types of particles (dust, smoke, fog, spray, asbestos), including bacteria, viruses and radioactive deposits. Very high efficiency. Fits on all Sundström half- and full masks, and fan system. If gas/vapors and particles are present at the same time, combine the particle filter with appropriate gas filter. Carton: 10 boxes of 5 pcs.