Hi, I want to use a size for image category and other different size for the subCategory image (CategoryChild) is that possible? I read post like this but there is no clear answer or way to do it. Thank you very much!! :)

Regards!

No one? Please help!! :(

Go to line 375 in k2.css and add in width: 300px; before the final }.
Be sure to create an override folder in your joomla template folder first or everything you've done will be lost at the next upgrade.