Tough, high density polyester in a 24-strand weave. These are great all-purpose boots for hikers or work boots. Dual-Layer Weave Stays Tied In the production process, the outer weave is wrapped around a high density core. This creates some just enough stretch to lock the laces in place when tied. 30% More Density A 24-strand polyester weave gives these 30% higher density than a typical polyester boot lace. Tough enough for most applications, job site or back country.