1.stainless steel and designed to over 10 years. 304 contains at least 18% chromium, which provides excellent corrosion and oxidation resistance. It's easy to wash away residues, keep shinning after a long use. 2.The strainer prevents leaves, seeds and other debris clogging gutter downspout, keeps the water flow free. You're still going to occasionally clean out the debris accumulated around the strainer, much easier to clear the downspout inside. 3.Suitable for outdoor, outdoor, rooftop terrace and other ground water demand, to prevent the blockage of flowers, leaves and other debris. 4.Measure the inner size of downspout, no tools required, simply push them into holes. Specifications: Product Name: Stainless steel roof floor drain Colour:silver Material: stainless steel Size:about 3 inch, fit for 2.5 ~ 3.7 inch hole size Package Contents: 4*stainless steel roof floor drain Note: 1.Only the above package content, other products are not included. 2. Light shooting and different displPXCL may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +\/- 1-3cm.