These are the sturdiest mats yet! Woven from float-rope used by lobstermen, who are now required to use sink-rope in hope to decrease the amount of entangled sea life, especially the Northern Atlantic Right Whale. They thrive under the harshest of conditions, trapping dirt, mud, snow, and sand. Resistant to mold, mildew, salt water and sun. Use of this recycled rope takes it from going straight to landfills. Handwoven in Maine.