WEARWELL® Clean Zone Mats are ideal for indoor entrances with heavy traffic. Polypropylene construcion. 5/16" thick. The best olefin entrance mat for controlling moisture—holds up to 2-1/4 gals. of water per sq. yd. Long wearing, abrasion-resistant surface with looped pile that resists crushing. Vinyl back resists mildew. 1" border. Made in USA.