RD series air operated diaphragm pumps sizes vary from 3/8 to 4 inch inlet/outlet, The pump body is made of various material, including PP, acetal, PVDF, Al, SST, CI, etc, which with high quality and good-looking appearance, is very similar to Graco's, but much cheaper than it. Being widely used for diverse industries, such as chemical industry, coating & painting industry, textile industry, beverage & food industry, water treatment industry, etc to transport fluid, our pumps have been receiving lots of good comments.