The SR 700 is a battery-powered fan that, together with particle filter SR 510 P3 R or SR 710 P3 R and an approved head top, is included in the Sundström fan-assisted respiratory protective device systems. The SR 700 can be used as an alternative to filter respirators in all situations in which these are recommended. This applies particularly to work that is hard, warm or of long duration. The fan is equipped with filter, and the filtered air is fed through a hose to the human interface. The pressure then generated prevents surrounding pollutants from penetrating into the mask.