This Module allows you to enable Filters on all parent and sub categories, without having to assign them individually to every category. Just assign filters to the products and they show up on the category pages.
A better explanation: Default (problem): Every time a new filter (ex: size or price or color etc) is created or assigned to a product, you have to also assign these filters to the parent and sub categories of the product. And all the filters assigned to the category are shown on category page irrespective of products.
Solution With This Module: You just have to assign filters to products ONLY ONCE and the category pages will auto populate the relevant filters of the products and show them.