The Redline K-9 Sport All Weather Biothane Leash is crafted from heavy duty 5/8" BioThane Beta® 520, a waterproof and vulcanized rubber material that prevents moisture retention and rot. It has a remarkable break strength of 1000 pounds per inch of width. Available in a variety of colors, each size features our heavy-duty 5/8" bolt-snap in your choice of brass or stainless steel.