These gutter guards are made of non-corrosive and waterproof aluminum, unaffected by weather and robust for long-term use. The diameter of this gutter guard is approximately 3 inches, fitting 2.5 ~ 3.7 inch hole sizes. Suitable for outdoor use, rooftop terraces, and other ground water needs. Install Them in Seconds Unlike other impractical gutter filter screens, the downspout leaf guards can be installed in seconds without using any tools. You don't need to be an expert or call a professional. Just push them into place and you're ready! A Must-Have for Every Gutter System By preventing leaves, debris, twigs, roof moss, and dirt from clogging your pipes, you can easily ensure your gutter system remains in perfect condition for longer without the need for expensive repairs and constant unclogging. You are now ensuring your gutters and downspouts are protected from leaf debris, roof moss, twigs, and dirt. 4 for a set, enough for daily use.