class that defines the featured image

Hi
I use LEAP and
I need to exclude the featured image from the head of each post from being lazy loaded By LEAP.
I can exclude by URL Attribute Element Class or Text.
I know how to do it by URL but this means that I need one rule for each post. I am expecting to solve the exclusion with only one rule.

Which would be the best way to define the featured image, only the big image on top, not the thumbnails of featured images.

Thanks in advance

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