It is made up of 304 Grade Stainless Steel, high-quality material, rust resistant, strong endurance, and durable in all conditions, even salt water. Stainless Steel Construction, looks great and provides years of service. The flagpole is strong at high speed and the flag flutters, suitable for yachts, marines, RVs, fishing boats, and so on. Easy to install and easy to adjust Clamps up and down to fit your flag size, easy and fast to replace flags. Dimensions: Pole Diameter: 1/2 inches (12.7mm); Length: 21 inches (533.4mm); Fits tubing: 7/8 to 1 inch. Package Includes 1 piece of Marine City 304 Grade Stainless Steel Rail Mount Flag Staff and White Plastic Flag Pole Base.