> For the complete documentation index, see [llms.txt](https://docs.buildingtransparency.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.buildingtransparency.org/ec3/main-features/find-and-compare-materials/using-specification-filters.md). # Using Specification Filters ## Math operators You can adjust the math operators inside the fields to modify the search algorithm to include results with exact, approximate, below, and above the specified value.

Click the math operator inside the field.

Select which operator you want to use.

Approximate operator search for values within 10% of the entered value.

## Options lists You can search for products that have a specific characteristic by including or excluding products with that characteristic from the search. * Include products with a specific property by clicking the property 1x (see Property - **Yes**) * Exclude products with a specific property by clicking the property 2x (see Property - **No**)

Number of clicks toggles a multi-select options on or off.

{% hint style="warning" %} Individual EPDs must have the properties that are relevant to them filled out on their EPD pages. If an EPD is missing a property that it should have, it won't show up in user searches that make that property part of the search. Because EC3 sometimes lists properties that are useful or critical for comparisons, but not all EPDs report those properties, you may not get the results you wanted or anticipated. We encourage manufacturers with EPDs in EC3 to add these properties, and all users to submit **Report Bugs & Feedback** about missing properties so that the Building Transparency team can add those properties and make the search more useful. {% endhint %} ## Removing filters You can remove filters, even the default filters, by clicking the red X button inside the search chip.

Click X to remove a filter.