Notrax 161 Barrier Rib Entrance Mat, for Indoor Main Entranceways and Heavy Traffic Areas, 3' Width x 4' Length x 3/8" Thickness, Gray Molded dual-ridge cross-rib pattern (a NoTrax exclusive) facilitates scraping and drying, retaining moisture and debris within its patented/invisible Aqua Dam border Extremely durable, yet highly fashionable look featuring carpet-to-the-edge to blend with its surroundings, use for Indoor - main entranceways; any and all heavy traffic areas Anti-Microbial carpet treatment to stop bacteria and germs at the entrance Densely tufted yarn for increased moisture retention; rubber underside features a cleat design which resists mat slippage Recommended and approved product as a part of the GreenTRAX program for Green Cleaning environments (when used as part of the Stages system)