Here are the short specifications for both the 3-inch and 4-inch industrial metal foot valves based on the product details:
3-Inch Industrial Foot Valve Spec
Type: Industrial water pump foot valve / non-return valve
Size: 3 inches
Material / Finish: Golden-chromate coated heavy-duty steel/metal body with brassy metallic tone
Design: Perforated cylindrical strainer body, flanged connection with bolts, and a barbed hose tail base
Origin: Made in China
4-Inch Industrial Foot Valve Spec
Type: Industrial water pump foot valve / non-return valve
Size: 4 inches