Usage Tips:These gutter strainers are made of non-corrosive and waterproof Aluminum, which is not affected by weather and robust for long-term use. The diameter of this gutter strainer approx. 3 inch, fits for 2.5 ~ 3.7 inch hole size. Suitable for outdoor, rooftop terrace and other ground water demand. Install Them In Seconds Unlike other impractical gutter filters, the downpipe leaf guards can be installed in seconds without using any tools. You dont have to be an expert or call a professional. Simply push them into place and youre good to go! A Must-Have for Every Guttering System By preventing leaf debris, twigs, roof moss and dirt from clogging your pipes, you can easily make sure that your guttering system stays in perfect condition for longer without the need for costly repairs and constant unclogging. You now make sure that your gutters and down pipes are protected from leaf debris, roof moss, twigs and dirt. 4 for a set, enough for daily use