Where do interior mats belong?
Indoor or interior mats function either as the second in a row when the visitor has already passed through the first (outdoor) cleaning mat; the latter then serves to remove finer dirt (dust, moisture). Alternatively, they are quite sufficient for areas with lower traffic, where they can catch most of the common dirt on the soles of shoes themselves. The surface of the interior mats can then be even softer, which absorbs moisture well and cleans smaller deposits of dirt.