Designed to provide optimal protection against rain. The WaterFlex material features a polyurethane (PU) rubber exterior with an inner microfleece lining. It is waterproof, flexible, and durable. The 38 mm wide Velcro strap allows these covers to be used for (inline) skates. All seams are covered internally with waterproof tape. There are two reinforced sections between the sole and the zipper, as well as at the front. It includes an industrial-strength YKK zipper.