SR 561 TH3 Tyvec hood together with the battery-driven SR 500, SR 500 EX or SR 700 fan and approved filters are included in Sundström fan-assisted respiratory protective devices. The breathing hose of the hood is connected to the fan which is equipped with a filter. The pressure generated in the hood prevents particles and other impurities from being admitted into the hood. The hood can also be used with the SR 507 compressed air equipment. This combination forms a breathing apparatus designed for continuous air flow, for connection to a compressed air supply. The equipment can be used as an alternative to filter protections in all situations in which the latter are recommended. This applies particularly to situations in which the work is intensive, hot or of long duration.