When the F+W Proportioner used in vehicle mounted system or mobile fire extinguishing systems, it can be equipped with a double-head plunger pump to achieve 3% and 6% mixing ratio switching, and can also be combined with mixing ratio adjustment technology to achieve 1% and 2% 3%，4%，5%，6% adjustment. When the mixing ratio of 3% is required, one plunger pump runs in the suction state, and the other plunger pump runs in the flushing state, when the mixing ratio of 6% is required, the two plunger pumps are in the suction state, and only the operation of the three-way valve can be achieved.

For vehicle mounted applications, the three-way valve can be equipped with a pneumatic or electric actuator for easy remote operation.