The Clean Stride mat features a WaterHog mat followed by an adhesive surface that captures smaller dust and dirt.  Just two steps on a Clean Stride adhesive insert removes over 90% of dirt particles, making this mat ideal for clean rooms, healthcare facilities, school gymnasiums, server rooms, and other areas sensitive to dirt and dust particles. Raised nubs on the WaterHog mat remove dirt and moisture from shoes and trap it below foot level while the adhesive insert removes any remaining dirt or dust particles Adhesive inserts sold separately, each with 60 numbered layers Not recommended for wet areas