Sundström breathing hose are tested and approved together with the following products, and are intended for use with Sundström SR 500, SR 500 EX and SR 700 battery-powered fan units. SR 200 Full face mask. SR 200 Airline compressed air-fed mask. SR 550 Plastic hose made of PU with durable spring steel spiral. Chemical-resistant. The hose are delivered complete with couplings.