DURAK Poly-Strong PC WR is a strong water repellent poly-cotton thread where the polyester core is covered with cotton. Its special lubrication gives it a high degree of water resistance. This thread then is the perfect choice for out-door products, shoes and items that need such protection. A PFC free, water resistant finishing agent ensures that thread absorbs no water. Correct tension also prevents water entering the stitching holes. Its high strength and optimal extension give shoes for example smooth and attractive seams.