DOW FROTH-PAK™ Fan Spray Nozzles are designed for use with the FROTH-PAK™ Foam System. They provide large volume coverage for spraying walls, roof lines or other vertical or horizontal surfaces. Each nozzle clips on to the dispenser gun and is the section where the 2 chemicals come together and mix with a stream of pressurized air. Because the chemicals react immediately the nozzles become clogged when spraying stops and are designed to be replaced.