The portable One Seven proportioning system OSP-24i-T is an electrically driven positive pressure proportioning system to deliver and admix foaming agent to water. Up to six nozzles can be supplied with wetting agent simultaneously via manifolds. When using appropriate foam nozzles low expansion foam and medium expansion foam can be produced. The OSP24i-T can be carried comfortably by two persons and thus be located and used very flexibly. The construction with robust frame and protective housing enables the use under rough operating conditions. The foaming agent is metered automatically and highly accurate on the basis of the preset proportioning rate and the currently measured water volume flow. Deviations in the calculated delivery volume (e.g. due to viscosity changes caused by temperature fluctuations) are detected by high-precision sensors and are automatically adjusted by the system. The integrated plunger pump is suitable for all foaming agents approved for firefighting up to a viscosity of 500 mPa*s. Of particular interest is the possibility of using modern „highperformance“ foaming agents with proportioning rates of economical 0.3 - 1.0%. Intuitive operation is done via an integrated 5-inch color display with touchscreen. This display also shows the measured sensor data for system monitoring