Switches from foam to water without shutting down. A check valve with a polyethylene ball keeps water from flowing back into the emulsifier tank, while a re-entering device regulates the concentration flow and percentage of foam liquid. 6-1/4" x 3", comes with suction hose, stainless steel pick up tube. By-pass 0.4%, 1%, 3% and 6% metering devices. Weighs 2.2 lbs.