Create air-rich foam with Dramm's Compression Foamer. This foaming sprayer produces an aerated foam that slowly degrades over time, allowing for more contact time. The air is pumped by hand into the 5L chamber, pressurizing the spray solution. The compressed air is mixed with the spray solution to create foam. The foam comes from three different mixing valves to allow for different solution ratios and different qualities of foam. Treats up to 500 sq ft. Relief valve auto opens at 60 psi.