Special features: The new unit works with an admixing rate adjustable in steps of 0.3%, 0.7%, 1%, 2% and 3%. Thereby all extinguishing agents form low surface tension water to foam are possible. The minimum flow is 100 l/min, the maximum flow 1000 l/min. Under all operation conditions the quality of the foam is equal. Changing flow rates, changing pressure and back pressure or different viscosities do not influence the function of the units.