Construction: Made up of 304 Grade Stainless Steel, high-quality, sturdy material that provides a long service life. HIGHLY POLISHED: Finely polished surface, louvered style, provides maximum corrosion resistance and durability. The fabric design makes it more suitable for use in outdoor environments. Easy to install, and convenient to use, the special tab can help you hold it tightly, suitable for related vents in boats, marines, yachts, caravans, and homes. Easy to install, and convenient to use, the special tab can help you hold it tightly, suitable for related vents in boats, marines, yachts, caravans, and homes. Package Includes 1 piece of Marine City 304 Grade Stainless Steel Hose Vent 4 inches diameter for boats.