The Mod. MLF is a Venturi type fixed line mixer that works on the basis of the negative pressure generated when water passes through different piping sections. When in operation the MLF proportioner inducts foam concentrate from an atmospheric storage tank and injects ii into the water stream, providing a 1 %, 3% or 6% foam solution. The Mod. MLF is manufactured in stainless steel with Venturi in bronze and equipped with a metering and shut off valve that allows foam induction to be regulated and stopped. This type of mixers can be used for metering foam in water in small fixed applications with a fixed flow rate.